siponimod (Rx)

Multiple Sclerosis

Indicated for relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease

Patients with CYP2C9 genotypes *1/*1, *1/*2, or *2/*2

• Initiate with a 5-day titration
• Maintenance dose (Day 6): 2 mg PO qDay
• Use a starter pack for patients who will be titrated to the 2-mg maintenance dosage
• Do not use starter pack for patients who will be titrated to the 1-mg maintenance dosage

• Titration for the 2-mg/day maintenance dose

  • Day 1: 0.25 mg (1 x 0.25 mg) PO
  • Day 2: 0.25 mg (1 x 0.25 mg) PO
  • Day 3: 0.50 mg (2 x 0.25 mg) PO
  • Day 4: 0.75 mg (3 x 0.25 mg) PO
  • Day 5: 1.25 mg (5 x 0.25 mg) PO
  • Day 6 and thereafter: 2 mg (1 x 2 mg) PO qDay

Patients with CYP2C9 genotypes *1/*3 or *2/*3

• Initiate with a 4-day titration
• Maintenance dose (Day 5): 1 mg PO qDay
• Do not use the starter pack for patients who will be titrated to the 1-mg maintenance dosage

• Titration for 1-mg/day maintenance dose

  • Day 1: 0.25 mg (1 x 0.25 mg) PO
  • Day 2: 0.25 mg (1 x 0.25 mg) PO
  • Day 3 0.50 mg (2 x 0.25 mg) PO
  • Day 4: 0.75 mg (3 x 0.25 mg) PO
  • Day 5 and thereafter: 1 mg (4 x 0.25 mg) PO qDay

Reinitiation after treatment interruption

• After completing initial titration, if maintenance treatment is interrupted for 4 or more consecutive daily doses, reinitiate treatment with Day 1 of the titration regimen
• Also complete first-dose monitoring in patients for whom it is recommended

Dosage Modifications

Renal impairment

• No dosage adjustment necessary
• End-stage renal disease or patients on hemodialysis: Not studied; owing to high plasma protein binding (>99.9%) of siponimod, hemodialysis is not expected to alter the total and unbound siponimod concentration and no dose adjustments are anticipated based on these considerations

Hepatic impairment

• No dosage adjustment necessary
• Increased unbound siponimod AUC observed with moderate and severe hepatic impairment is not expected to be clinically significant

Dosing Considerations

Before initiating treatment

• Test for CYP2C9 variants to determine CYP2C9 genotype; an FDA-cleared or FDA-approved test for detecting CYP2C9 variants to direct the use of siponimod is not currently available
• Test for antibodies to varicella-zoster virus (VZV); VZV vaccination of antibody-negative patients is recommended prior to commencing treatment
• Determine whether patients are taking drugs that could slow heart rate or atrioventricular (AV) conduction
• If patients are taking or have a history of taking antineoplastic, immunosuppressive, or immune-modulating therapies, consider possible unintended additive immunosuppressive effects before initiating treatment
• Ophthalmic examination, including evaluation of the fundus, including the macula
• Electrocardiogram (ECG)
• Recent CBC count
• Recent (eg, within last 6 months) transaminase and bilirubin levels
• If varicella zoster virus (VZV) antibody-negative, administer full course VZV vaccine and postpone siponimod initiation for 4 week to allow full vaccine efficacy

First-dose monitoring in patients with certain preexisting cardiac conditions

• Because initiating treatment results in a decrease in heart rate (HR), recommend first-dose 6-hr monitoring for patients with sinus bradycardia (HR <55 bpm), first- or second-degree (Mobitz type I) AV block, or a history of myocardial infarction or heart failure

• If any of the following abnormalities are present after 6 hr (even in the absence of symptoms):

  • HR 6 hr postdose <45 bpm or is at the lowest value postdose
  • ECG 6 hr postdose shows new-onset second-degree or higher AV block
  • Monitor until the abnormality resolves
• If postdose symptomatic bradycardia, bradyarrhythmia, or conduction related symptoms occur, or if ECG 6 hr postdose shows new-onset second-degree or higher AV block or QTc ≥500 msec, initiate appropriate management; monitor ECG and symptoms until resolved if no pharmacological treatment is required
• If pharmacological treatment is required, monitor overnight and repeat 6-hr monitoring after second dose
• Consult with a cardiologist for patients with preexisting heart and cerebrovascular conditions, a prolonged QTc interval before dosing or during the 6-hr observation, at additional risk for QT prolongation, or on concurrent therapy with QT-prolonging drugs with a known risk of torsades de pointes or drugs that slow heart rate or AV conduction

Safety and efficacy not established

Contraindicated (3)

• lefamulin

  lefamulin will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Lefamulin is contraindicated with CYP3A substrates know to prolong the QT interval.

• saquinavir

  siponimod and saquinavir both increase QTc interval. Contraindicated.

• thioridazine

  siponimod and thioridazine both increase QTc interval. Contraindicated.

Serious - Use Alternative (277)

• adenovirus types 4 and 7 live, oral

  siponimod decreases effects of adenovirus types 4 and 7 live, oral by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• alemtuzumab

  siponimod and alemtuzumab both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Because of the characteristics and duration of alemtuzumab immune suppressive effects, initiating treatment with siponimod after alemtuzumab is not recommended.

• alfuzosin

  alfuzosin and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• amiodarone

  siponimod, amiodarone. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.
  
  amiodarone will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  amiodarone will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• amisulpride

  amisulpride and siponimod both increase QTc interval. Avoid or Use Alternate Drug. ECG monitoring is recommended if coadministered.

• amobarbital

  amobarbital will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• anagrelide

  siponimod and anagrelide both increase QTc interval. Avoid or Use Alternate Drug.

• anthrax vaccine adsorbed

  siponimod decreases effects of anthrax vaccine adsorbed by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• apalutamide

  apalutamide will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• apomorphine

  apomorphine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• aprepitant

  aprepitant will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• aripiprazole

  aripiprazole and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• armodafinil

  armodafinil will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• arsenic trioxide

  siponimod and arsenic trioxide both increase QTc interval. Avoid or Use Alternate Drug.

• artemether

  artemether and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• artemether/lumefantrine

  artemether/lumefantrine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• asenapine

  siponimod and asenapine both increase QTc interval. Avoid or Use Alternate Drug.

• asenapine transdermal

  asenapine transdermal and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• atazanavir

  atazanavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• atomoxetine

  atomoxetine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• azithromycin

  siponimod and azithromycin both increase QTc interval. Avoid or Use Alternate Drug.

• BCG vaccine live

  siponimod decreases effects of BCG vaccine live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• bedaquiline

  bedaquiline and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• bexarotene

  bexarotene will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• bicalutamide

  bicalutamide will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• bosentan

  bosentan will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• brigatinib

  brigatinib will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• buprenorphine

  siponimod and buprenorphine both increase QTc interval. Avoid or Use Alternate Drug.

• buprenorphine buccal

  buprenorphine buccal and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• buprenorphine subdermal implant

  buprenorphine subdermal implant and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• buprenorphine transdermal

  buprenorphine transdermal and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• buprenorphine, long-acting injection

  buprenorphine, long-acting injection and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• butabarbital

  butabarbital will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• butalbital

  butalbital will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• capecitabine

  capecitabine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• carbamazepine

  carbamazepine will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• ceritinib

  ceritinib will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  ceritinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  ceritinib and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• chloramphenicol

  chloramphenicol will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• chloroquine

  chloroquine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• chlorpromazine

  siponimod and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• cholera vaccine

  siponimod decreases effects of cholera vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• ciprofloxacin

  siponimod and ciprofloxacin both increase QTc interval. Avoid or Use Alternate Drug.

• citalopram

  citalopram and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• clarithromycin

  clarithromycin will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  clarithromycin and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• clobazam

  clobazam will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• clozapine

  clozapine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• cobicistat

  cobicistat will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• crizotinib

  crizotinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  crizotinib and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• cyclosporine

  cyclosporine will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• dabrafenib

  dabrafenib will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• darunavir

  darunavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• dasatinib

  dasatinib and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• degarelix

  degarelix and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• desflurane

  desflurane and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• digoxin

  siponimod, digoxin. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• diltiazem

  siponimod, diltiazem. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.
  
  diltiazem will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• diphtheria & tetanus toxoids

  siponimod decreases effects of diphtheria & tetanus toxoids by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• diphtheria & tetanus toxoids/ acellular pertussis vaccine

  siponimod decreases effects of diphtheria & tetanus toxoids/ acellular pertussis vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• diphtheria & tetanus toxoids/acellular pertussis/poliovirus, inactivated vaccine

  siponimod decreases effects of diphtheria & tetanus toxoids/acellular pertussis/poliovirus, inactivated vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• disopyramide

  siponimod, disopyramide. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• dofetilide

  siponimod, dofetilide. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• dolasetron

  dolasetron and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• donepezil

  donepezil and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• doxycycline

  doxycycline will increase the level or effect of siponimod by affecting hepatic enzyme CYP2E1 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• dronedarone

  siponimod, dronedarone. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.
  
  dronedarone will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• droperidol

  siponimod and droperidol both increase QTc interval. Avoid or Use Alternate Drug.

• efavirenz

  efavirenz will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  efavirenz will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.
  
  efavirenz and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• eliglustat

  siponimod and eliglustat both increase QTc interval. Avoid or Use Alternate Drug.

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  elvitegravir/cobicistat/emtricitabine/tenofovir DF will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• encorafenib

  encorafenib will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.
  
  encorafenib and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• entrectinib

  entrectinib and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• enzalutamide

  enzalutamide will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• eribulin

  eribulin and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin base

  erythromycin base will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and erythromycin base both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin ethylsuccinate

  erythromycin ethylsuccinate will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and erythromycin ethylsuccinate both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin lactobionate

  erythromycin lactobionate will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and erythromycin lactobionate both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin stearate

  erythromycin stearate will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and erythromycin stearate both increase QTc interval. Avoid or Use Alternate Drug.

• escitalopram

  siponimod and escitalopram both increase QTc interval. Avoid or Use Alternate Drug.

• eslicarbazepine acetate

  eslicarbazepine acetate will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• etravirine

  etravirine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  etravirine will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• fexinidazole

  fexinidazole and siponimod both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels or prolong QT interval.
  
  fexinidazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.

• fingolimod

  fingolimod and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• flecainide

  siponimod and flecainide both increase QTc interval. Avoid or Use Alternate Drug.

• fluconazole

  fluconazole will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  fluconazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and fluconazole both increase QTc interval. Avoid or Use Alternate Drug.

• fluorouracil

  fluorouracil will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• fluoxetine

  siponimod and fluoxetine both increase QTc interval. Avoid or Use Alternate Drug.

• flurbiprofen

  flurbiprofen will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• fluvastatin

  fluvastatin will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• fluvoxamine

  fluvoxamine will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor not recommended
  
  siponimod and fluvoxamine both increase QTc interval. Avoid or Use Alternate Drug.

• fosamprenavir

  fosamprenavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• fosaprepitant

  fosaprepitant will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• foscarnet

  siponimod and foscarnet both increase QTc interval. Avoid or Use Alternate Drug.

• fosphenytoin

  fosphenytoin will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• fostamatinib

  fostamatinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• gemfibrozil

  gemfibrozil will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• gemifloxacin

  gemifloxacin and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• gemtuzumab

  siponimod and gemtuzumab both increase QTc interval. Avoid or Use Alternate Drug.

• gilteritinib

  gilteritinib and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• glasdegib

  siponimod and glasdegib both increase QTc interval. Avoid or Use Alternate Drug.

• goserelin

  siponimod and goserelin both increase QTc interval. Avoid or Use Alternate Drug.

• granisetron

  granisetron and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• grapefruit

  grapefruit will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• haemophilus influenzae type b vaccine

  siponimod decreases effects of haemophilus influenzae type b vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• haloperidol

  haloperidol will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.

• hepatitis A vaccine inactivated

  siponimod decreases effects of hepatitis A vaccine inactivated by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• hepatitis a/b vaccine

  siponimod decreases effects of hepatitis a/b vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• hepatitis b vaccine

  siponimod decreases effects of hepatitis b vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• histrelin

  siponimod and histrelin both increase QTc interval. Avoid or Use Alternate Drug.

• HIV vaccine

  siponimod decreases effects of HIV vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• human papillomavirus vaccine, nonavalent

  siponimod decreases effects of human papillomavirus vaccine, nonavalent by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• human papillomavirus vaccine, quadrivalent

  siponimod decreases effects of human papillomavirus vaccine, quadrivalent by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• hydroxychloroquine sulfate

  siponimod and hydroxychloroquine sulfate both increase QTc interval. Avoid or Use Alternate Drug.

• hydroxyzine

  hydroxyzine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• ibuprofen

  ibuprofen will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• ibutilide

  siponimod, ibutilide. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• idelalisib

  idelalisib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• iloperidone

  iloperidone will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and iloperidone both increase QTc interval. Avoid or Use Alternate Drug.

• imatinib

  imatinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• indinavir

  indinavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• indomethacin

  indomethacin will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• influenza A (H5N1) vaccine

  siponimod decreases effects of influenza A (H5N1) vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine (H5N1), adjuvanted

  siponimod decreases effects of influenza virus vaccine (H5N1), adjuvanted by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine quadrivalent

  siponimod decreases effects of influenza virus vaccine quadrivalent by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine quadrivalent, adjuvanted

  siponimod decreases effects of influenza virus vaccine quadrivalent, adjuvanted by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine quadrivalent, cell-cultured

  siponimod decreases effects of influenza virus vaccine quadrivalent, cell-cultured by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine quadrivalent, intranasal

  siponimod decreases effects of influenza virus vaccine quadrivalent, intranasal by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine quadrivalent, recombinant

  siponimod decreases effects of influenza virus vaccine quadrivalent, recombinant by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine trivalent

  siponimod decreases effects of influenza virus vaccine trivalent by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine trivalent, adjuvanted

  siponimod decreases effects of influenza virus vaccine trivalent, adjuvanted by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine trivalent, recombinant

  siponimod decreases effects of influenza virus vaccine trivalent, recombinant by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• inotuzumab

  siponimod and inotuzumab both increase QTc interval. Avoid or Use Alternate Drug.

• irbesartan

  irbesartan will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• isoflurane

  isoflurane and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• isoniazid

  isoniazid will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• itraconazole

  itraconazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  itraconazole and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• ivabradine

  siponimod, ivabradine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• ivacaftor

  ivacaftor will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• ivosidenib

  ivosidenib will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.
  
  siponimod and ivosidenib both decrease QTc interval. Avoid or Use Alternate Drug.

• Japanese encephalitis virus vaccine

  siponimod decreases effects of Japanese encephalitis virus vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• ketoconazole

  ketoconazole will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  ketoconazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• lapatinib

  lapatinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and lapatinib both increase QTc interval. Avoid or Use Alternate Drug.

• larotrectinib

  larotrectinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• lefamulin

  siponimod and lefamulin both increase QTc interval. Avoid or Use Alternate Drug.

• lenvatinib

  siponimod and lenvatinib both increase QTc interval. Avoid or Use Alternate Drug.

• letermovir

  letermovir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• leuprolide

  siponimod and leuprolide both increase QTc interval. Avoid or Use Alternate Drug.

• levofloxacin

  siponimod and levofloxacin both increase QTc interval. Avoid or Use Alternate Drug.

• levoketoconazole

  levoketoconazole will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  levoketoconazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• lithium

  lithium and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• lofexidine

  siponimod and lofexidine both increase QTc interval. Avoid or Use Alternate Drug.

• lonafarnib

  lonafarnib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with sensitive CYP3A substrates. If coadministration unavoidable, monitor for adverse reactions and reduce CYP3A substrate dose in accordance with product labeling.

• lopinavir

  lopinavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and lopinavir both increase QTc interval. Avoid or Use Alternate Drug.

• lorlatinib

  lorlatinib will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• losartan

  losartan will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• lumacaftor/ivacaftor

  lumacaftor/ivacaftor will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• macimorelin

  siponimod and macimorelin both increase QTc interval. Avoid or Use Alternate Drug.

• maprotiline

  siponimod and maprotiline both increase QTc interval. Avoid or Use Alternate Drug.

• measles (rubeola) vaccine

  siponimod decreases effects of measles (rubeola) vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• measles mumps and rubella vaccine, live

  siponimod decreases effects of measles mumps and rubella vaccine, live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• measles, mumps, rubella and varicella vaccine, live

  siponimod decreases effects of measles, mumps, rubella and varicella vaccine, live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• mefenamic acid

  mefenamic acid will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• mefloquine

  siponimod and mefloquine both increase QTc interval. Avoid or Use Alternate Drug.

• meningococcal A C Y and W-135 diphtheria conjugate vaccine

  siponimod decreases effects of meningococcal A C Y and W-135 diphtheria conjugate vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• meningococcal A C Y and W-135 polysaccharide vaccine combined

  siponimod decreases effects of meningococcal A C Y and W-135 polysaccharide vaccine combined by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• meningococcal group B vaccine

  siponimod decreases effects of meningococcal group B vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• methadone

  siponimod and methadone both increase QTc interval. Avoid or Use Alternate Drug.

• metronidazole

  metronidazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• midostaurin

  siponimod and midostaurin both increase QTc interval. Avoid or Use Alternate Drug.

• mifepristone

  mifepristone will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and mifepristone both increase QTc interval. Avoid or Use Alternate Drug.

• mirtazapine

  mirtazapine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• mitotane

  mitotane will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• mobocertinib

  siponimod and mobocertinib both increase QTc interval. Avoid or Use Alternate Drug.

• moxifloxacin

  siponimod and moxifloxacin both increase QTc interval. Avoid or Use Alternate Drug.

• nafcillin

  nafcillin will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• nefazodone

  nefazodone will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• nelfinavir

  nelfinavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• netupitant/palonosetron

  netupitant/palonosetron will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• nicardipine

  nicardipine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• nilotinib

  siponimod and nilotinib both increase QTc interval. Avoid or Use Alternate Drug.

• nitisinone

  nitisinone will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• octreotide

  siponimod and octreotide both increase QTc interval. Avoid or Use Alternate Drug.

• ofloxacin

  siponimod and ofloxacin both increase QTc interval. Avoid or Use Alternate Drug.

• olanzapine

  olanzapine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  olanzapine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• omeprazole

  omeprazole will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• ondansetron

  siponimod and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

• osimertinib

  siponimod and osimertinib both increase QTc interval. Avoid or Use Alternate Drug.

• oxaliplatin

  oxaliplatin and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• paliperidone

  siponimod and paliperidone both increase QTc interval. Avoid or Use Alternate Drug.

• panobinostat

  siponimod and panobinostat both increase QTc interval. Avoid or Use Alternate Drug.

• pasireotide

  siponimod and pasireotide both increase QTc interval. Avoid or Use Alternate Drug.

• pazopanib

  siponimod and pazopanib both increase QTc interval. Avoid or Use Alternate Drug.

• pentamidine

  siponimod and pentamidine both increase QTc interval. Avoid or Use Alternate Drug.

• pentobarbital

  pentobarbital will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• phenobarbital

  phenobarbital will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• phenytoin

  phenytoin will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• pimavanserin

  siponimod and pimavanserin both increase QTc interval. Avoid or Use Alternate Drug.

• pimozide

  siponimod and pimozide both increase QTc interval. Contraindicated.

• piroxicam

  piroxicam will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• pitolisant

  siponimod and pitolisant both increase QTc interval. Avoid or Use Alternate Drug.

• pneumococcal vaccine 13-valent

  siponimod decreases effects of pneumococcal vaccine 13-valent by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• pneumococcal vaccine heptavalent

  siponimod decreases effects of pneumococcal vaccine heptavalent by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• pneumococcal vaccine polyvalent

  siponimod decreases effects of pneumococcal vaccine polyvalent by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• poliovirus vaccine inactivated

  siponimod decreases effects of poliovirus vaccine inactivated by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• ponesimod

  ponesimod, siponimod. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Consult cardiologist if considering treatment. Coadministration of ponesimod with drugs that decrease HR may have additive effects on decreasing HR and should generally not be initiated in these patients.

• posaconazole

  posaconazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and posaconazole both increase QTc interval. Avoid or Use Alternate Drug.

• primaquine

  primaquine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• primidone

  primidone will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• procainamide

  siponimod, procainamide. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• promethazine

  siponimod and promethazine both decrease QTc interval. Avoid or Use Alternate Drug.

• propafenone

  siponimod and propafenone both increase QTc interval. Avoid or Use Alternate Drug.

• pyrimethamine

  pyrimethamine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• quetiapine

  siponimod and quetiapine both increase QTc interval. Avoid or Use Alternate Drug.

• quinidine

  siponimod, quinidine. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• quinine

  quinine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  siponimod and quinine both increase QTc interval. Avoid or Use Alternate Drug.

• quinupristin/dalfopristin

  quinupristin/dalfopristin will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• rabies vaccine

  siponimod decreases effects of rabies vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• rabies vaccine chick embryo cell derived

  siponimod decreases effects of rabies vaccine chick embryo cell derived by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• ranolazine

  siponimod and ranolazine both increase QTc interval. Avoid or Use Alternate Drug.

• ribociclib

  ribociclib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and ribociclib both increase QTc interval. Avoid or Use Alternate Drug.

• rifabutin

  rifabutin will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• rifampin

  rifampin will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• rifapentine

  rifapentine will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• rilpivirine

  siponimod and rilpivirine both increase QTc interval. Avoid or Use Alternate Drug.

• risperidone

  siponimod and risperidone both increase QTc interval. Avoid or Use Alternate Drug.

• ritonavir

  ritonavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• romidepsin

  siponimod and romidepsin both increase QTc interval. Avoid or Use Alternate Drug.

• rotavirus oral vaccine, live

  siponimod decreases effects of rotavirus oral vaccine, live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• rubella vaccine

  siponimod decreases effects of rubella vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• saquinavir

  saquinavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• schisandra

  schisandra will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• secobarbital

  secobarbital will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• selpercatinib

  siponimod and selpercatinib both increase QTc interval. Avoid or Use Alternate Drug.

• sertraline

  sertraline will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  sertraline and siponimod both increase QTc interval. Avoid or Use Alternate Drug.
  
  siponimod and sertraline both increase QTc interval. Avoid or Use Alternate Drug.

• sevoflurane

  sevoflurane and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• smallpox (vaccinia) and monkeypox vaccine, live, nonreplicating

  siponimod decreases effects of smallpox (vaccinia) vaccine, attenuated by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• smallpox (vaccinia) vaccine, attenuated

  siponimod decreases effects of smallpox (vaccinia) vaccine, attenuated by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• smallpox (vaccinia) vaccine, live

  siponimod decreases effects of smallpox (vaccinia) vaccine, live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• solifenacin

  siponimod and solifenacin both increase QTc interval. Avoid or Use Alternate Drug.
  
  solifenacin and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• sorafenib

  sorafenib will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  siponimod and sorafenib both increase QTc interval. Avoid or Use Alternate Drug.

• sotalol

  siponimod, sotalol. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• St John's Wort

  St John's Wort will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• sulfadiazine

  sulfadiazine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• sulfamethoxazole

  sulfamethoxazole will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• sunitinib

  siponimod and sunitinib both increase QTc interval. Avoid or Use Alternate Drug.
  
  sunitinib and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• tacrolimus

  siponimod and tacrolimus both increase QTc interval. Avoid or Use Alternate Drug.

• telavancin

  siponimod and telavancin both increase QTc interval. Avoid or Use Alternate Drug.

• telotristat ethyl

  telotristat ethyl will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• tetanus & reduced diphtheria toxoids/ acellular pertussis vaccine

  siponimod decreases effects of tetanus & reduced diphtheria toxoids/ acellular pertussis vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• tetanus toxoid adsorbed or fluid

  siponimod decreases effects of tetanus toxoid adsorbed or fluid by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• tetrabenazine

  siponimod and tetrabenazine both increase QTc interval. Avoid or Use Alternate Drug.

• tetracycline

  tetracycline will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• tipranavir

  tipranavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• tolbutamide

  tolbutamide will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• toremifene

  siponimod and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

• trazodone

  siponimod and trazodone both increase QTc interval. Avoid or Use Alternate Drug.

• triclabendazole

  siponimod and triclabendazole both increase QTc interval. Avoid or Use Alternate Drug.

• trimethoprim

  trimethoprim will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• triptorelin

  siponimod and triptorelin both increase QTc interval. Avoid or Use Alternate Drug.

• tucatinib

  tucatinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.

• typhoid polysaccharide vaccine

  siponimod decreases effects of typhoid polysaccharide vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• typhoid vaccine live

  siponimod decreases effects of typhoid vaccine live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• upadacitinib

  siponimod, upadacitinib. Either increases effects of the other by immunosuppressive effects; risk of infection. Contraindicated.

• vandetanib

  siponimod and vandetanib both increase QTc interval. Avoid or Use Alternate Drug.

• vardenafil

  siponimod and vardenafil both increase QTc interval. Avoid or Use Alternate Drug.

• varicella virus vaccine live

  siponimod decreases effects of varicella virus vaccine live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• vemurafenib

  siponimod and vemurafenib both increase QTc interval. Avoid or Use Alternate Drug.

• venlafaxine

  siponimod and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• verapamil

  siponimod, verapamil. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.
  
  verapamil will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• voclosporin

  siponimod and voclosporin both increase QTc interval. Avoid or Use Alternate Drug.

• voriconazole

  voriconazole will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  voriconazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and voriconazole both increase QTc interval. Avoid or Use Alternate Drug.

• vorinostat

  siponimod and vorinostat both increase QTc interval. Avoid or Use Alternate Drug.

• voxelotor

  voxelotor will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.

• yellow fever vaccine

  siponimod decreases effects of yellow fever vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• zafirlukast

  zafirlukast will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• ziprasidone

  siponimod and ziprasidone both increase QTc interval. Avoid or Use Alternate Drug.

• zoster vaccine live

  siponimod decreases effects of zoster vaccine live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• zoster vaccine recombinant

  siponimod decreases effects of zoster vaccine recombinant by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

Monitor Closely (293)

• abatacept

  siponimod and abatacept both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• abemaciclib

  siponimod and abemaciclib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• abiraterone

  siponimod and abiraterone both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• acalabrutinib

  siponimod and acalabrutinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• acebutolol

  siponimod, acebutolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• ado-trastuzumab emtansine

  siponimod and ado-trastuzumab emtansine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• afatinib

  siponimod and afatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• albuterol

  albuterol and siponimod both increase QTc interval. Use Caution/Monitor.

• aldesleukin

  siponimod and aldesleukin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• alectinib

  siponimod and alectinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• alitretinoin topical

  siponimod and alitretinoin topical both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• alpelisib

  alpelisib will decrease the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Modify Therapy/Monitor Closely.

• anakinra

  siponimod and anakinra both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• anastrozole

  siponimod and anastrozole both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• antithymocyte globulin equine

  siponimod and antithymocyte globulin equine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• antithymocyte globulin rabbit

  siponimod and antithymocyte globulin rabbit both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• apalutamide

  siponimod and apalutamide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• apaziquone

  siponimod and apaziquone both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• arformoterol

  arformoterol and siponimod both increase QTc interval. Use Caution/Monitor.

• arsenic trioxide

  siponimod and arsenic trioxide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• asparaginase Erwinia chrysanthemi

  siponimod and asparaginase Erwinia chrysanthemi both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• atenolol

  siponimod, atenolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• atezolizumab

  siponimod and atezolizumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• avelumab

  siponimod and avelumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• axitinib

  siponimod and axitinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• azacitidine

  siponimod and azacitidine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• azathioprine

  siponimod and azathioprine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• basiliximab

  siponimod and basiliximab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• BCG intravesical live

  siponimod and BCG intravesical live both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• belatacept

  siponimod and belatacept both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• belinostat

  siponimod and belinostat both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• bendamustine

  siponimod and bendamustine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• betaxolol

  siponimod, betaxolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• bevacizumab

  siponimod and bevacizumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• bexarotene

  siponimod and bexarotene both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• bicalutamide

  siponimod and bicalutamide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• binimetinib

  siponimod and binimetinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• bisoprolol

  siponimod, bisoprolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• bleomycin

  siponimod and bleomycin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• blinatumomab

  siponimod and blinatumomab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• bortezomib

  siponimod and bortezomib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• bosutinib

  siponimod and bosutinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• brentuximab vedotin

  siponimod and brentuximab vedotin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• brigatinib

  siponimod and brigatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• busulfan

  siponimod and busulfan both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• C1 esterase inhibitor recombinant

  siponimod and C1 esterase inhibitor recombinant both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• C1 inhibitor human

  siponimod and C1 inhibitor human both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• cabazitaxel

  siponimod and cabazitaxel both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• cabozantinib

  siponimod and cabozantinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• capecitabine

  siponimod and capecitabine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• carboplatin

  siponimod and carboplatin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• carfilzomib

  siponimod and carfilzomib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• carmustine

  siponimod and carmustine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• carvedilol

  siponimod, carvedilol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• celiprolol

  siponimod, celiprolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• cemiplimab

  siponimod and cemiplimab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• cenobamate

  cenobamate will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.

• ceritinib

  siponimod and ceritinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• certolizumab pegol

  siponimod and certolizumab pegol both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• cetuximab

  siponimod and cetuximab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• chlorambucil

  siponimod and chlorambucil both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• cisplatin

  siponimod and cisplatin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• cladribine

  siponimod and cladribine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• clofarabine

  siponimod and clofarabine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• cobimetinib

  siponimod and cobimetinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• conivaptan

  conivaptan will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration with a moderate of strong CYP3A4 inhibitor plus a moderate or strong CYP2C9 inhibitor not recommended

• copanlisib

  siponimod and copanlisib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• crizotinib

  siponimod and crizotinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• custirsen

  siponimod and custirsen both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• cyclophosphamide

  siponimod and cyclophosphamide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• cyclosporine

  siponimod, cyclosporine. Either increases effects of the other by immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• cytarabine

  siponimod and cytarabine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• dabrafenib

  siponimod and dabrafenib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.
  
  siponimod and dabrafenib both increase QTc interval. Use Caution/Monitor.

• dacarbazine

  siponimod and dacarbazine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• dacomitinib

  siponimod and dacomitinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• dactinomycin

  siponimod and dactinomycin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• daratumumab

  siponimod and daratumumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• dasatinib

  siponimod and dasatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• daunorubicin

  siponimod and daunorubicin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• decitabine

  siponimod and decitabine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• degarelix

  siponimod and degarelix both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• denosumab

  siponimod and denosumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• deutetrabenazine

  deutetrabenazine and siponimod both increase QTc interval. Use Caution/Monitor. At the maximum recommended dose, deutetrabenazine does not prolong QT interval to a clinically relevant extent. Certain circumstances may increase risk of torsade de pointes and/or sudden death in association with drugs that prolong the QTc interval (eg, bradycardia, hypokalemia or hypomagnesemia, coadministration with other drugs that prolong QTc interval, presence of congenital QT prolongation).

• dimethyl fumarate

  siponimod and dimethyl fumarate both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• dinutuximab

  siponimod and dinutuximab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• diroximel fumarate

  siponimod and diroximel fumarate both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• docetaxel

  siponimod and docetaxel both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• doxepin

  doxepin and siponimod both increase QTc interval. Use Caution/Monitor.

• doxorubicin

  siponimod and doxorubicin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• doxorubicin liposomal

  siponimod and doxorubicin liposomal both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• durvalumab

  siponimod and durvalumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• duvelisib

  siponimod and duvelisib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• elagolix

  elagolix decreases levels of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.

• elotuzumab

  siponimod and elotuzumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• emapalumab

  siponimod and emapalumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• encorafenib

  siponimod and encorafenib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• entrectinib

  siponimod and entrectinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• enzalutamide

  siponimod and enzalutamide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• epirubicin

  siponimod and epirubicin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• erdafitinib

  siponimod and erdafitinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• eribulin

  siponimod and eribulin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• erlotinib

  siponimod and erlotinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• esmolol

  siponimod, esmolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• estramustine

  siponimod and estramustine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• estrogens esterified

  siponimod and estrogens esterified both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• etanercept

  siponimod and etanercept both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• etoposide

  siponimod and etoposide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• everolimus

  siponimod and everolimus both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• exemestane

  siponimod and exemestane both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• fedratinib

  siponimod and fedratinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.
  
  fedratinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• fingolimod

  siponimod and fingolimod both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• floxuridine

  siponimod and floxuridine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• fludarabine

  siponimod and fludarabine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• fluorouracil

  siponimod and fluorouracil both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• fluphenazine

  siponimod and fluphenazine both increase QTc interval. Use Caution/Monitor.

• flutamide

  siponimod and flutamide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• fostamatinib

  siponimod and fostamatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• fostemsavir

  siponimod and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.

• fulvestrant

  siponimod and fulvestrant both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• gefitinib

  siponimod and gefitinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• gemcitabine

  siponimod and gemcitabine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• gemtuzumab

  siponimod and gemtuzumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• gilteritinib

  siponimod and gilteritinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• glasdegib

  siponimod and glasdegib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• glatiramer

  siponimod and glatiramer both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immune effects during such therapy and in the weeks following administration. Siponimod can generally be started immediately after discontinuation of glatiramer.

• goserelin

  siponimod and goserelin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• histrelin

  siponimod and histrelin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• hydroxychloroquine sulfate

  siponimod and hydroxychloroquine sulfate both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• hydroxyurea

  siponimod and hydroxyurea both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ibritumomab tiuxetan

  siponimod and ibritumomab tiuxetan both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ibrutinib

  siponimod and ibrutinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• icatibant

  siponimod and icatibant both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• idarubicin

  siponimod and idarubicin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• idelalisib

  siponimod and idelalisib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ifosfamide

  siponimod and ifosfamide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• imatinib

  siponimod and imatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• infliximab

  siponimod and infliximab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• inotuzumab

  siponimod and inotuzumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• interferon alfa 2b

  siponimod and interferon alfa 2b both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• interferon alfa n3

  siponimod and interferon alfa n3 both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• interferon beta 1a

  siponimod and interferon beta 1a both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immune effects during such therapy and in the weeks following administration. Siponimod can generally be started immediately after discontinuation of beta interferon.

• interferon beta 1b

  siponimod and interferon beta 1b both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immune effects during such therapy and in the weeks following administration. Siponimod can generally be started immediately after discontinuation of beta interferon.

• interferon gamma 1b

  siponimod and interferon gamma 1b both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• iobenguane I 131

  siponimod and iobenguane I 131 both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ipilimumab

  siponimod and ipilimumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• irinotecan

  siponimod and irinotecan both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• irinotecan liposomal

  siponimod and irinotecan liposomal both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• istradefylline

  istradefylline will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.

• ivosidenib

  siponimod and ivosidenib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ixabepilone

  siponimod and ixabepilone both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ixazomib

  siponimod and ixazomib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• labetalol

  siponimod, labetalol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• lapatinib

  siponimod and lapatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• larotrectinib

  siponimod and larotrectinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• leflunomide

  siponimod and leflunomide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• lenalidomide

  siponimod and lenalidomide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• lenvatinib

  siponimod and lenvatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• letrozole

  siponimod and letrozole both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• leuprolide

  siponimod and leuprolide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• lomustine

  siponimod and lomustine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• loperamide

  siponimod and loperamide both increase QTc interval. Use Caution/Monitor.

• lorlatinib

  siponimod and lorlatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• lutetium Lu 177-dota-tate

  siponimod and lutetium Lu 177-dota-tate both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• mechlorethamine

  siponimod and mechlorethamine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• mechlorethamine topical

  siponimod and mechlorethamine topical both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• medroxyprogesterone

  siponimod and medroxyprogesterone both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• megestrol

  siponimod and megestrol both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• melphalan

  siponimod and melphalan both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• mercaptopurine

  siponimod and mercaptopurine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• methotrexate

  siponimod and methotrexate both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• methyltestosterone

  siponimod and methyltestosterone both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• metoprolol

  siponimod, metoprolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• midostaurin

  siponimod and midostaurin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• mitomycin

  siponimod and mitomycin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• mitotane

  siponimod and mitotane both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• mitoxantrone

  siponimod and mitoxantrone both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• mogamulizumab

  siponimod and mogamulizumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• moxetumomab pasudotox

  siponimod and moxetumomab pasudotox both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• muromonab CD3

  siponimod and muromonab CD3 both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• mycophenolate

  siponimod and mycophenolate both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• nadolol

  siponimod, nadolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• nebivolol

  siponimod, nebivolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• necitumumab

  siponimod and necitumumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• nelarabine

  siponimod and nelarabine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• neratinib

  siponimod and neratinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• nilotinib

  siponimod and nilotinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• nilutamide

  siponimod and nilutamide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• niraparib

  siponimod and niraparib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• nivolumab

  siponimod and nivolumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• obinutuzumab

  siponimod and obinutuzumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ofatumumab

  siponimod and ofatumumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ofatumumab SC

  ofatumumab SC, siponimod. Either increases effects of the other by immunosuppressive effects; risk of infection. Use Caution/Monitor. Consider the risk of additive immune system effects when coadministering immunosuppressive therapies with coadministration. When switching from therapies with immune effects, take into account the duration and mechanism of action of these therapies when initiating ofatumumab SC.

• olaparib

  siponimod and olaparib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• olaratumab

  siponimod and olaratumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• omacetaxine

  siponimod and omacetaxine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• osilodrostat

  osilodrostat and siponimod both increase QTc interval. Use Caution/Monitor.

• osimertinib

  siponimod and osimertinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• oxaliplatin

  siponimod and oxaliplatin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ozanimod

  ozanimod, siponimod. Either increases effects of the other by immunosuppressive effects; risk of infection. Use Caution/Monitor. Coadministration with immunosuppressive therapies may increase the risk of additive immune effects during therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs in order to avoid unintended additive immunosuppressive effects.

• paclitaxel

  siponimod and paclitaxel both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• paclitaxel protein bound

  siponimod and paclitaxel protein bound both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• pacritinib

  siponimod and pacritinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• palbociclib

  siponimod and palbociclib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• palifermin

  siponimod and palifermin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• panitumumab

  siponimod and panitumumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• panobinostat

  siponimod and panobinostat both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• pazopanib

  siponimod and pazopanib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• pegaspargase

  siponimod and pegaspargase both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• peginterferon beta-1a

  siponimod and peginterferon beta-1a both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immune effects during such therapy and in the weeks following administration. Siponimod can generally be started immediately after discontinuation of beta interferon.

• pegloticase

  siponimod and pegloticase both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• pembrolizumab

  siponimod and pembrolizumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• pemetrexed

  siponimod and pemetrexed both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• penbutolol

  siponimod, penbutolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• pentostatin

  siponimod and pentostatin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• perphenazine

  siponimod and perphenazine both increase QTc interval. Use Caution/Monitor.

• pertuzumab

  siponimod and pertuzumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• pexidartinib

  siponimod and pexidartinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• pindolol

  siponimod, pindolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• polatuzumab vedotin

  siponimod and polatuzumab vedotin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• pomalidomide

  siponimod and pomalidomide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ponatinib

  siponimod and ponatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• porfimer

  siponimod and porfimer both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• pralatrexate

  siponimod and pralatrexate both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• procarbazine

  siponimod and procarbazine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• prochlorperazine

  siponimod and prochlorperazine both decrease QTc interval. Use Caution/Monitor.

• propranolol

  siponimod, propranolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• quizartinib

  siponimod and quizartinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• radium-223 dichloride

  siponimod and radium-223 dichloride both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ramucirumab

  siponimod and ramucirumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• rasburicase

  siponimod and rasburicase both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• regorafenib

  siponimod and regorafenib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ribociclib

  siponimod and ribociclib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• rilonacept

  siponimod and rilonacept both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• rituximab

  siponimod and rituximab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• rituximab-hyaluronidase

  siponimod and rituximab-hyaluronidase both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• romidepsin

  siponimod and romidepsin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• rucaparib

  siponimod and rucaparib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ruxolitinib

  siponimod and ruxolitinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• sacituzumab govitecan

  siponimod and sacituzumab govitecan both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• samarium sm 153 lexidronam

  siponimod and samarium sm 153 lexidronam both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• siltuximab

  siponimod and siltuximab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• sipuleucel-T

  siponimod decreases effects of sipuleucel-T by pharmacodynamic antagonism. Modify Therapy/Monitor Closely.

• sirolimus

  siponimod and sirolimus both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• sirolimus intravitreal

  siponimod and sirolimus intravitreal both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• sirukumab

  siponimod and sirukumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• sodium iodide I-131

  siponimod and sodium iodide I-131 both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• sonidegib

  siponimod and sonidegib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• sorafenib

  siponimod and sorafenib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• sotalol

  siponimod, sotalol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• sparsentan

  sparsentan will decrease the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. Sparsentan (a CYP2C9 inducer) decreases exposure of CYP2C9 substrates and reduces efficacy related to these substrates.

• streptozocin

  siponimod and streptozocin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• strontium 89 chloride

  siponimod and strontium 89 chloride both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• sunitinib

  siponimod and sunitinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• tacrolimus

  siponimod and tacrolimus both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• tagraxofusp

  siponimod and tagraxofusp both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• talazoparib

  siponimod and talazoparib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• tamoxifen

  siponimod and tamoxifen both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• tazemetostat

  siponimod and tazemetostat both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.
  
  tazemetostat will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• technetium Tc 99m tilmanocept

  siponimod and technetium Tc 99m tilmanocept both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• temozolomide

  siponimod and temozolomide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• temsirolimus

  siponimod and temsirolimus both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• teniposide

  siponimod and teniposide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• thalidomide

  siponimod and thalidomide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• thioguanine

  siponimod and thioguanine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• thiotepa

  siponimod and thiotepa both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• timolol

  siponimod, timolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• tivozanib

  siponimod and tivozanib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• tocilizumab

  siponimod and tocilizumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• tofacitinib

  siponimod and tofacitinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• topotecan

  siponimod and topotecan both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• toremifene

  siponimod and toremifene both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• tositumomab

  siponimod and tositumomab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• trabectedin

  siponimod and trabectedin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• trametinib

  siponimod and trametinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• trastuzumab

  siponimod and trastuzumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• trastuzumab deruxtecan

  siponimod and trastuzumab deruxtecan both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• tretinoin

  siponimod and tretinoin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• trifluoperazine

  siponimod and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• trifluridine/tipiracil

  siponimod and trifluridine/tipiracil both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• triptorelin

  siponimod and triptorelin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• tumor necrosis factor-alpha (TNF-alpha) adenovector

  siponimod and tumor necrosis factor-alpha (TNF-alpha) adenovector both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• valbenazine

  valbenazine and siponimod both increase QTc interval. Use Caution/Monitor.

• valrubicin

  siponimod and valrubicin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• vandetanib

  siponimod and vandetanib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• vemurafenib

  siponimod and vemurafenib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• venetoclax

  siponimod and venetoclax both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• vinblastine

  siponimod and vinblastine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• vincristine

  siponimod and vincristine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• vincristine liposomal

  siponimod and vincristine liposomal both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• vinorelbine

  siponimod and vinorelbine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• vismodegib

  siponimod and vismodegib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• vorinostat

  siponimod and vorinostat both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ziv-aflibercept

  siponimod and ziv-aflibercept both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

Minor (3)

• acetazolamide

  acetazolamide will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• anastrozole

  anastrozole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• cyclophosphamide

  cyclophosphamide will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• abatacept

  Monitor Closely (1)siponimod and abatacept both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• abemaciclib

  Monitor Closely (1)siponimod and abemaciclib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• abiraterone

  Monitor Closely (1)siponimod and abiraterone both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• acalabrutinib

  Monitor Closely (1)siponimod and acalabrutinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• acebutolol

  Monitor Closely (1)siponimod, acebutolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• acetazolamide

  Minor (1)acetazolamide will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• adenovirus types 4 and 7 live, oral

  Serious - Use Alternative (1)siponimod decreases effects of adenovirus types 4 and 7 live, oral by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• ado-trastuzumab emtansine

  Monitor Closely (1)siponimod and ado-trastuzumab emtansine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• afatinib

  Monitor Closely (1)siponimod and afatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• albuterol

  Monitor Closely (1)albuterol and siponimod both increase QTc interval. Use Caution/Monitor.

• aldesleukin

  Monitor Closely (1)siponimod and aldesleukin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• alectinib

  Monitor Closely (1)siponimod and alectinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• alemtuzumab

  Serious - Use Alternative (1)siponimod and alemtuzumab both increase immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Because of the characteristics and duration of alemtuzumab immune suppressive effects, initiating treatment with siponimod after alemtuzumab is not recommended.

• alfuzosin

  Serious - Use Alternative (1)alfuzosin and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• alitretinoin topical

  Monitor Closely (1)siponimod and alitretinoin topical both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• alpelisib

  Monitor Closely (1)alpelisib will decrease the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Modify Therapy/Monitor Closely.

• amiodarone

  Serious - Use Alternative (3)siponimod, amiodarone. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.
  
  amiodarone will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  amiodarone will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• amisulpride

  Serious - Use Alternative (1)amisulpride and siponimod both increase QTc interval. Avoid or Use Alternate Drug. ECG monitoring is recommended if coadministered.

• amobarbital

  Serious - Use Alternative (1)amobarbital will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• anagrelide

  Serious - Use Alternative (1)siponimod and anagrelide both increase QTc interval. Avoid or Use Alternate Drug.

• anakinra

  Monitor Closely (1)siponimod and anakinra both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• anastrozole

  Monitor Closely (1)siponimod and anastrozole both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Minor (1)anastrozole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• anthrax vaccine adsorbed

  Serious - Use Alternative (1)siponimod decreases effects of anthrax vaccine adsorbed by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• antithymocyte globulin equine

  Monitor Closely (1)siponimod and antithymocyte globulin equine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• antithymocyte globulin rabbit

  Monitor Closely (1)siponimod and antithymocyte globulin rabbit both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• apalutamide

  Monitor Closely (1)siponimod and apalutamide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)apalutamide will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• apaziquone

  Monitor Closely (1)siponimod and apaziquone both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• apomorphine

  Serious - Use Alternative (1)apomorphine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• aprepitant

  Serious - Use Alternative (1)aprepitant will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• arformoterol

  Monitor Closely (1)arformoterol and siponimod both increase QTc interval. Use Caution/Monitor.

• aripiprazole

  Serious - Use Alternative (1)aripiprazole and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• armodafinil

  Serious - Use Alternative (1)armodafinil will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• arsenic trioxide

  Monitor Closely (1)siponimod and arsenic trioxide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and arsenic trioxide both increase QTc interval. Avoid or Use Alternate Drug.

• artemether

  Serious - Use Alternative (1)artemether and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• artemether/lumefantrine

  Serious - Use Alternative (1)artemether/lumefantrine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• asenapine

  Serious - Use Alternative (1)siponimod and asenapine both increase QTc interval. Avoid or Use Alternate Drug.

• asenapine transdermal

  Serious - Use Alternative (1)asenapine transdermal and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• asparaginase Erwinia chrysanthemi

  Monitor Closely (1)siponimod and asparaginase Erwinia chrysanthemi both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• atazanavir

  Serious - Use Alternative (1)atazanavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• atenolol

  Monitor Closely (1)siponimod, atenolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• atezolizumab

  Monitor Closely (1)siponimod and atezolizumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• atomoxetine

  Serious - Use Alternative (1)atomoxetine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• avelumab

  Monitor Closely (1)siponimod and avelumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• axitinib

  Monitor Closely (1)siponimod and axitinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• azacitidine

  Monitor Closely (1)siponimod and azacitidine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• azathioprine

  Monitor Closely (1)siponimod and azathioprine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• azithromycin

  Serious - Use Alternative (1)siponimod and azithromycin both increase QTc interval. Avoid or Use Alternate Drug.

• basiliximab

  Monitor Closely (1)siponimod and basiliximab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• BCG intravesical live

  Monitor Closely (1)siponimod and BCG intravesical live both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• BCG vaccine live

  Serious - Use Alternative (1)siponimod decreases effects of BCG vaccine live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• bedaquiline

  Serious - Use Alternative (1)bedaquiline and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• belatacept

  Monitor Closely (1)siponimod and belatacept both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• belinostat

  Monitor Closely (1)siponimod and belinostat both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• bendamustine

  Monitor Closely (1)siponimod and bendamustine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• betaxolol

  Monitor Closely (1)siponimod, betaxolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• bevacizumab

  Monitor Closely (1)siponimod and bevacizumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• bexarotene

  Monitor Closely (1)siponimod and bexarotene both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)bexarotene will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• bicalutamide

  Monitor Closely (1)siponimod and bicalutamide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)bicalutamide will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• binimetinib

  Monitor Closely (1)siponimod and binimetinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• bisoprolol

  Monitor Closely (1)siponimod, bisoprolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• bleomycin

  Monitor Closely (1)siponimod and bleomycin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• blinatumomab

  Monitor Closely (1)siponimod and blinatumomab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• bortezomib

  Monitor Closely (1)siponimod and bortezomib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• bosentan

  Serious - Use Alternative (1)bosentan will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• bosutinib

  Monitor Closely (1)siponimod and bosutinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• brentuximab vedotin

  Monitor Closely (1)siponimod and brentuximab vedotin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• brigatinib

  Monitor Closely (1)siponimod and brigatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)brigatinib will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• buprenorphine

  Serious - Use Alternative (1)siponimod and buprenorphine both increase QTc interval. Avoid or Use Alternate Drug.

• buprenorphine buccal

  Serious - Use Alternative (1)buprenorphine buccal and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• buprenorphine subdermal implant

  Serious - Use Alternative (1)buprenorphine subdermal implant and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• buprenorphine transdermal

  Serious - Use Alternative (1)buprenorphine transdermal and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• buprenorphine, long-acting injection

  Serious - Use Alternative (1)buprenorphine, long-acting injection and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• busulfan

  Monitor Closely (1)siponimod and busulfan both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• butabarbital

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• butalbital

  Serious - Use Alternative (1)butalbital will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• C1 esterase inhibitor recombinant

  Monitor Closely (1)siponimod and C1 esterase inhibitor recombinant both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• C1 inhibitor human

  Monitor Closely (1)siponimod and C1 inhibitor human both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• cabazitaxel

  Monitor Closely (1)siponimod and cabazitaxel both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• cabozantinib

  Monitor Closely (1)siponimod and cabozantinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• capecitabine

  Monitor Closely (1)siponimod and capecitabine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)capecitabine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• carbamazepine

  Serious - Use Alternative (1)carbamazepine will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• carboplatin

  Monitor Closely (1)siponimod and carboplatin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• carfilzomib

  Monitor Closely (1)siponimod and carfilzomib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• carmustine

  Monitor Closely (1)siponimod and carmustine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• carvedilol

  Monitor Closely (1)siponimod, carvedilol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• celiprolol

  Monitor Closely (1)siponimod, celiprolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• cemiplimab

  Monitor Closely (1)siponimod and cemiplimab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• cenobamate

  Monitor Closely (1)cenobamate will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.

• ceritinib

  Monitor Closely (1)siponimod and ceritinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (3)ceritinib will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  ceritinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  ceritinib and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• certolizumab pegol

  Monitor Closely (1)siponimod and certolizumab pegol both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• cetuximab

  Monitor Closely (1)siponimod and cetuximab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• chlorambucil

  Monitor Closely (1)siponimod and chlorambucil both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• chloramphenicol

  Serious - Use Alternative (1)chloramphenicol will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• chloroquine

  Serious - Use Alternative (1)chloroquine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• chlorpromazine

  Serious - Use Alternative (1)siponimod and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• cholera vaccine

  Serious - Use Alternative (1)siponimod decreases effects of cholera vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• ciprofloxacin

  Serious - Use Alternative (1)siponimod and ciprofloxacin both increase QTc interval. Avoid or Use Alternate Drug.

• cisplatin

  Monitor Closely (1)siponimod and cisplatin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• citalopram

  Serious - Use Alternative (1)citalopram and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• cladribine

  Monitor Closely (1)siponimod and cladribine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• clarithromycin

  Serious - Use Alternative (2)clarithromycin will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  clarithromycin and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• clobazam

  Serious - Use Alternative (1)clobazam will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• clofarabine

  Monitor Closely (1)siponimod and clofarabine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• clozapine

  Serious - Use Alternative (1)clozapine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• cobicistat

  Serious - Use Alternative (1)cobicistat will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• cobimetinib

  Monitor Closely (1)siponimod and cobimetinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• conivaptan

  Monitor Closely (1)conivaptan will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration with a moderate of strong CYP3A4 inhibitor plus a moderate or strong CYP2C9 inhibitor not recommended

• copanlisib

  Monitor Closely (1)siponimod and copanlisib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• crizotinib

  Monitor Closely (1)siponimod and crizotinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (2)crizotinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  crizotinib and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• custirsen

  Monitor Closely (1)siponimod and custirsen both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• cyclophosphamide

  Monitor Closely (1)siponimod and cyclophosphamide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Minor (1)cyclophosphamide will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• cyclosporine

  Monitor Closely (1)siponimod, cyclosporine. Either increases effects of the other by immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)cyclosporine will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• cytarabine

  Monitor Closely (1)siponimod and cytarabine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• dabrafenib

  Monitor Closely (2)siponimod and dabrafenib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.
  
  siponimod and dabrafenib both increase QTc interval. Use Caution/Monitor.Serious - Use Alternative (1)dabrafenib will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• dacarbazine

  Monitor Closely (1)siponimod and dacarbazine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• dacomitinib

  Monitor Closely (1)siponimod and dacomitinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• dactinomycin

  Monitor Closely (1)siponimod and dactinomycin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• daratumumab

  Monitor Closely (1)siponimod and daratumumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• darunavir

  Serious - Use Alternative (1)darunavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• dasatinib

  Monitor Closely (1)siponimod and dasatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)dasatinib and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• daunorubicin

  Monitor Closely (1)siponimod and daunorubicin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• decitabine

  Monitor Closely (1)siponimod and decitabine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• degarelix

  Monitor Closely (1)siponimod and degarelix both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)degarelix and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• denosumab

  Monitor Closely (1)siponimod and denosumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• desflurane

  Serious - Use Alternative (1)desflurane and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• deutetrabenazine

  Monitor Closely (1)deutetrabenazine and siponimod both increase QTc interval. Use Caution/Monitor. At the maximum recommended dose, deutetrabenazine does not prolong QT interval to a clinically relevant extent. Certain circumstances may increase risk of torsade de pointes and/or sudden death in association with drugs that prolong the QTc interval (eg, bradycardia, hypokalemia or hypomagnesemia, coadministration with other drugs that prolong QTc interval, presence of congenital QT prolongation).

• digoxin

  Serious - Use Alternative (1)siponimod, digoxin. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• diltiazem

  Serious - Use Alternative (2)siponimod, diltiazem. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.
  
  diltiazem will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• dimethyl fumarate

  Monitor Closely (1)siponimod and dimethyl fumarate both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• dinutuximab

  Monitor Closely (1)siponimod and dinutuximab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• diphtheria & tetanus toxoids

  Serious - Use Alternative (1)siponimod decreases effects of diphtheria & tetanus toxoids by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• diphtheria & tetanus toxoids/ acellular pertussis vaccine

  Serious - Use Alternative (1)siponimod decreases effects of diphtheria & tetanus toxoids/ acellular pertussis vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• diphtheria & tetanus toxoids/acellular pertussis/poliovirus, inactivated vaccine

  Serious - Use Alternative (1)siponimod decreases effects of diphtheria & tetanus toxoids/acellular pertussis/poliovirus, inactivated vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• diroximel fumarate

  Monitor Closely (1)siponimod and diroximel fumarate both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• disopyramide

  Serious - Use Alternative (1)siponimod, disopyramide. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• docetaxel

  Monitor Closely (1)siponimod and docetaxel both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• dofetilide

  Serious - Use Alternative (1)siponimod, dofetilide. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• dolasetron

  Serious - Use Alternative (1)dolasetron and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• donepezil

  Serious - Use Alternative (1)donepezil and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• doxepin

  Monitor Closely (1)doxepin and siponimod both increase QTc interval. Use Caution/Monitor.

• doxorubicin

  Monitor Closely (1)siponimod and doxorubicin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• doxorubicin liposomal

  Monitor Closely (1)siponimod and doxorubicin liposomal both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• doxycycline

  Serious - Use Alternative (1)doxycycline will increase the level or effect of siponimod by affecting hepatic enzyme CYP2E1 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• dronedarone

  Serious - Use Alternative (2)siponimod, dronedarone. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.
  
  dronedarone will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• droperidol

  Serious - Use Alternative (1)siponimod and droperidol both increase QTc interval. Avoid or Use Alternate Drug.

• durvalumab

  Monitor Closely (1)siponimod and durvalumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• duvelisib

  Monitor Closely (1)siponimod and duvelisib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• efavirenz

  Serious - Use Alternative (3)efavirenz will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  efavirenz will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.
  
  efavirenz and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• elagolix

  Monitor Closely (1)elagolix decreases levels of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.

• eliglustat

  Serious - Use Alternative (1)siponimod and eliglustat both increase QTc interval. Avoid or Use Alternate Drug.

• elotuzumab

  Monitor Closely (1)siponimod and elotuzumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  Serious - Use Alternative (1)elvitegravir/cobicistat/emtricitabine/tenofovir DF will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• emapalumab

  Monitor Closely (1)siponimod and emapalumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• encorafenib

  Monitor Closely (1)siponimod and encorafenib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (2)encorafenib will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.
  
  encorafenib and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• entrectinib

  Monitor Closely (1)siponimod and entrectinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)entrectinib and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• enzalutamide

  Monitor Closely (1)siponimod and enzalutamide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)enzalutamide will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• epirubicin

  Monitor Closely (1)siponimod and epirubicin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• erdafitinib

  Monitor Closely (1)siponimod and erdafitinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• eribulin

  Monitor Closely (1)siponimod and eribulin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)eribulin and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• erlotinib

  Monitor Closely (1)siponimod and erlotinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• erythromycin base

  Serious - Use Alternative (2)erythromycin base will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and erythromycin base both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin ethylsuccinate

  Serious - Use Alternative (2)erythromycin ethylsuccinate will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and erythromycin ethylsuccinate both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin lactobionate

  Serious - Use Alternative (2)erythromycin lactobionate will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and erythromycin lactobionate both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin stearate

  Serious - Use Alternative (2)erythromycin stearate will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and erythromycin stearate both increase QTc interval. Avoid or Use Alternate Drug.

• escitalopram

  Serious - Use Alternative (1)siponimod and escitalopram both increase QTc interval. Avoid or Use Alternate Drug.

• eslicarbazepine acetate

  Serious - Use Alternative (1)eslicarbazepine acetate will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• esmolol

  Monitor Closely (1)siponimod, esmolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• estramustine

  Monitor Closely (1)siponimod and estramustine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• estrogens esterified

  Monitor Closely (1)siponimod and estrogens esterified both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• etanercept

  Monitor Closely (1)siponimod and etanercept both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• etoposide

  Monitor Closely (1)siponimod and etoposide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• etravirine

  Serious - Use Alternative (2)etravirine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  etravirine will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• everolimus

  Monitor Closely (1)siponimod and everolimus both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• exemestane

  Monitor Closely (1)siponimod and exemestane both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• fedratinib

  Monitor Closely (2)siponimod and fedratinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.
  
  fedratinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• fexinidazole

  Serious - Use Alternative (2)fexinidazole and siponimod both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels or prolong QT interval.
  
  fexinidazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.

• fingolimod

  Monitor Closely (1)siponimod and fingolimod both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)fingolimod and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• flecainide

  Serious - Use Alternative (1)siponimod and flecainide both increase QTc interval. Avoid or Use Alternate Drug.

• floxuridine

  Monitor Closely (1)siponimod and floxuridine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• fluconazole

  Serious - Use Alternative (3)fluconazole will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  fluconazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and fluconazole both increase QTc interval. Avoid or Use Alternate Drug.

• fludarabine

  Monitor Closely (1)siponimod and fludarabine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• fluorouracil

  Monitor Closely (1)siponimod and fluorouracil both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)fluorouracil will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• fluoxetine

  Serious - Use Alternative (1)siponimod and fluoxetine both increase QTc interval. Avoid or Use Alternate Drug.

• fluphenazine

  Monitor Closely (1)siponimod and fluphenazine both increase QTc interval. Use Caution/Monitor.

• flurbiprofen

  Serious - Use Alternative (1)flurbiprofen will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• flutamide

  Monitor Closely (1)siponimod and flutamide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• fluvastatin

  Serious - Use Alternative (1)fluvastatin will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• fluvoxamine

  Serious - Use Alternative (2)fluvoxamine will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor not recommended
  
  siponimod and fluvoxamine both increase QTc interval. Avoid or Use Alternate Drug.

• fosamprenavir

  Serious - Use Alternative (1)fosamprenavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• fosaprepitant

  Serious - Use Alternative (1)fosaprepitant will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• foscarnet

  Serious - Use Alternative (1)siponimod and foscarnet both increase QTc interval. Avoid or Use Alternate Drug.

• fosphenytoin

  Serious - Use Alternative (1)fosphenytoin will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• fostamatinib

  Monitor Closely (1)siponimod and fostamatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)fostamatinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• fostemsavir

  Monitor Closely (1)siponimod and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.

• fulvestrant

  Monitor Closely (1)siponimod and fulvestrant both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• gefitinib

  Monitor Closely (1)siponimod and gefitinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• gemcitabine

  Monitor Closely (1)siponimod and gemcitabine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• gemfibrozil

  Serious - Use Alternative (1)gemfibrozil will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• gemifloxacin

  Serious - Use Alternative (1)gemifloxacin and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• gemtuzumab

  Monitor Closely (1)siponimod and gemtuzumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and gemtuzumab both increase QTc interval. Avoid or Use Alternate Drug.

• gilteritinib

  Monitor Closely (1)siponimod and gilteritinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)gilteritinib and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• glasdegib

  Monitor Closely (1)siponimod and glasdegib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and glasdegib both increase QTc interval. Avoid or Use Alternate Drug.

• glatiramer

  Monitor Closely (1)siponimod and glatiramer both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immune effects during such therapy and in the weeks following administration. Siponimod can generally be started immediately after discontinuation of glatiramer.

• goserelin

  Monitor Closely (1)siponimod and goserelin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and goserelin both increase QTc interval. Avoid or Use Alternate Drug.

• granisetron

  Serious - Use Alternative (1)granisetron and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• grapefruit

  Serious - Use Alternative (1)grapefruit will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• haemophilus influenzae type b vaccine

  Serious - Use Alternative (1)siponimod decreases effects of haemophilus influenzae type b vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• haloperidol

  Serious - Use Alternative (2)haloperidol will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.

• hepatitis A vaccine inactivated

  Serious - Use Alternative (1)siponimod decreases effects of hepatitis A vaccine inactivated by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• hepatitis a/b vaccine

  Serious - Use Alternative (1)siponimod decreases effects of hepatitis a/b vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• hepatitis b vaccine

  Serious - Use Alternative (1)siponimod decreases effects of hepatitis b vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• histrelin

  Monitor Closely (1)siponimod and histrelin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and histrelin both increase QTc interval. Avoid or Use Alternate Drug.

• HIV vaccine

  Serious - Use Alternative (1)siponimod decreases effects of HIV vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• human papillomavirus vaccine, nonavalent

  Serious - Use Alternative (1)siponimod decreases effects of human papillomavirus vaccine, nonavalent by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• human papillomavirus vaccine, quadrivalent

  Serious - Use Alternative (1)siponimod decreases effects of human papillomavirus vaccine, quadrivalent by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• hydroxychloroquine sulfate

  Monitor Closely (1)siponimod and hydroxychloroquine sulfate both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and hydroxychloroquine sulfate both increase QTc interval. Avoid or Use Alternate Drug.

• hydroxyurea

  Monitor Closely (1)siponimod and hydroxyurea both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• hydroxyzine

  Serious - Use Alternative (1)hydroxyzine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• ibritumomab tiuxetan

  Monitor Closely (1)siponimod and ibritumomab tiuxetan both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ibrutinib

  Monitor Closely (1)siponimod and ibrutinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ibuprofen

  Serious - Use Alternative (1)ibuprofen will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• ibutilide

  Serious - Use Alternative (1)siponimod, ibutilide. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• icatibant

  Monitor Closely (1)siponimod and icatibant both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• idarubicin

  Monitor Closely (1)siponimod and idarubicin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• idelalisib

  Monitor Closely (1)siponimod and idelalisib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)idelalisib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• ifosfamide

  Monitor Closely (1)siponimod and ifosfamide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• iloperidone

  Serious - Use Alternative (2)iloperidone will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and iloperidone both increase QTc interval. Avoid or Use Alternate Drug.

• imatinib

  Monitor Closely (1)siponimod and imatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)imatinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• indinavir

  Serious - Use Alternative (1)indinavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• indomethacin

  Serious - Use Alternative (1)indomethacin will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• infliximab

  Monitor Closely (1)siponimod and infliximab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• influenza A (H5N1) vaccine

  Serious - Use Alternative (1)siponimod decreases effects of influenza A (H5N1) vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine (H5N1), adjuvanted

  Serious - Use Alternative (1)siponimod decreases effects of influenza virus vaccine (H5N1), adjuvanted by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine quadrivalent

  Serious - Use Alternative (1)siponimod decreases effects of influenza virus vaccine quadrivalent by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine quadrivalent, adjuvanted

  Serious - Use Alternative (1)siponimod decreases effects of influenza virus vaccine quadrivalent, adjuvanted by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine quadrivalent, cell-cultured

  Serious - Use Alternative (1)siponimod decreases effects of influenza virus vaccine quadrivalent, cell-cultured by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine quadrivalent, intranasal

  Serious - Use Alternative (1)siponimod decreases effects of influenza virus vaccine quadrivalent, intranasal by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine quadrivalent, recombinant

  Serious - Use Alternative (1)siponimod decreases effects of influenza virus vaccine quadrivalent, recombinant by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine trivalent

  Serious - Use Alternative (1)siponimod decreases effects of influenza virus vaccine trivalent by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine trivalent, adjuvanted

  Serious - Use Alternative (1)siponimod decreases effects of influenza virus vaccine trivalent, adjuvanted by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• influenza virus vaccine trivalent, recombinant

  Serious - Use Alternative (1)siponimod decreases effects of influenza virus vaccine trivalent, recombinant by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• inotuzumab

  Monitor Closely (1)siponimod and inotuzumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and inotuzumab both increase QTc interval. Avoid or Use Alternate Drug.

• interferon alfa 2b

  Monitor Closely (1)siponimod and interferon alfa 2b both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• interferon alfa n3

  Monitor Closely (1)siponimod and interferon alfa n3 both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• interferon beta 1a

  Monitor Closely (1)siponimod and interferon beta 1a both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immune effects during such therapy and in the weeks following administration. Siponimod can generally be started immediately after discontinuation of beta interferon.

• interferon beta 1b

  Monitor Closely (1)siponimod and interferon beta 1b both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immune effects during such therapy and in the weeks following administration. Siponimod can generally be started immediately after discontinuation of beta interferon.

• interferon gamma 1b

  Monitor Closely (1)siponimod and interferon gamma 1b both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• iobenguane I 131

  Monitor Closely (1)siponimod and iobenguane I 131 both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ipilimumab

  Monitor Closely (1)siponimod and ipilimumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• irbesartan

  Serious - Use Alternative (1)irbesartan will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• irinotecan

  Monitor Closely (1)siponimod and irinotecan both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• irinotecan liposomal

  Monitor Closely (1)siponimod and irinotecan liposomal both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• isoflurane

  Serious - Use Alternative (1)isoflurane and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• isoniazid

  Serious - Use Alternative (1)isoniazid will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• istradefylline

  Monitor Closely (1)istradefylline will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.

• itraconazole

  Serious - Use Alternative (2)itraconazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  itraconazole and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• ivabradine

  Serious - Use Alternative (1)siponimod, ivabradine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• ivacaftor

  Serious - Use Alternative (1)ivacaftor will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• ivosidenib

  Monitor Closely (1)siponimod and ivosidenib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (2)ivosidenib will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.
  
  siponimod and ivosidenib both decrease QTc interval. Avoid or Use Alternate Drug.

• ixabepilone

  Monitor Closely (1)siponimod and ixabepilone both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ixazomib

  Monitor Closely (1)siponimod and ixazomib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• Japanese encephalitis virus vaccine

  Serious - Use Alternative (1)siponimod decreases effects of Japanese encephalitis virus vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• ketoconazole

  Serious - Use Alternative (2)ketoconazole will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  ketoconazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• labetalol

  Monitor Closely (1)siponimod, labetalol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• lapatinib

  Monitor Closely (1)siponimod and lapatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (2)lapatinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and lapatinib both increase QTc interval. Avoid or Use Alternate Drug.

• larotrectinib

  Monitor Closely (1)siponimod and larotrectinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)larotrectinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• lefamulin

  Contraindicated (1)lefamulin will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Lefamulin is contraindicated with CYP3A substrates know to prolong the QT interval.Serious - Use Alternative (1)siponimod and lefamulin both increase QTc interval. Avoid or Use Alternate Drug.

• leflunomide

  Monitor Closely (1)siponimod and leflunomide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• lenalidomide

  Monitor Closely (1)siponimod and lenalidomide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• lenvatinib

  Monitor Closely (1)siponimod and lenvatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and lenvatinib both increase QTc interval. Avoid or Use Alternate Drug.

• letermovir

  Serious - Use Alternative (1)letermovir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• letrozole

  Monitor Closely (1)siponimod and letrozole both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• leuprolide

  Monitor Closely (1)siponimod and leuprolide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and leuprolide both increase QTc interval. Avoid or Use Alternate Drug.

• levofloxacin

  Serious - Use Alternative (1)siponimod and levofloxacin both increase QTc interval. Avoid or Use Alternate Drug.

• levoketoconazole

  Serious - Use Alternative (2)levoketoconazole will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  levoketoconazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• lithium

  Serious - Use Alternative (1)lithium and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• lofexidine

  Serious - Use Alternative (1)siponimod and lofexidine both increase QTc interval. Avoid or Use Alternate Drug.

• lomustine

  Monitor Closely (1)siponimod and lomustine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• lonafarnib

  Serious - Use Alternative (1)lonafarnib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with sensitive CYP3A substrates. If coadministration unavoidable, monitor for adverse reactions and reduce CYP3A substrate dose in accordance with product labeling.

• loperamide

  Monitor Closely (1)siponimod and loperamide both increase QTc interval. Use Caution/Monitor.

• lopinavir

  Serious - Use Alternative (2)lopinavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and lopinavir both increase QTc interval. Avoid or Use Alternate Drug.

• lorlatinib

  Monitor Closely (1)siponimod and lorlatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)lorlatinib will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• losartan

  Serious - Use Alternative (1)losartan will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• lumacaftor/ivacaftor

  Serious - Use Alternative (1)lumacaftor/ivacaftor will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• lutetium Lu 177-dota-tate

  Monitor Closely (1)siponimod and lutetium Lu 177-dota-tate both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• macimorelin

  Serious - Use Alternative (1)siponimod and macimorelin both increase QTc interval. Avoid or Use Alternate Drug.

• maprotiline

  Serious - Use Alternative (1)siponimod and maprotiline both increase QTc interval. Avoid or Use Alternate Drug.

• measles (rubeola) vaccine

  Serious - Use Alternative (1)siponimod decreases effects of measles (rubeola) vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• measles mumps and rubella vaccine, live

  Serious - Use Alternative (1)siponimod decreases effects of measles mumps and rubella vaccine, live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• measles, mumps, rubella and varicella vaccine, live

  Serious - Use Alternative (1)siponimod decreases effects of measles, mumps, rubella and varicella vaccine, live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• mechlorethamine

  Monitor Closely (1)siponimod and mechlorethamine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• mechlorethamine topical

  Monitor Closely (1)siponimod and mechlorethamine topical both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• medroxyprogesterone

  Monitor Closely (1)siponimod and medroxyprogesterone both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• mefenamic acid

  Serious - Use Alternative (1)mefenamic acid will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• mefloquine

  Serious - Use Alternative (1)siponimod and mefloquine both increase QTc interval. Avoid or Use Alternate Drug.

• megestrol

  Monitor Closely (1)siponimod and megestrol both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• melphalan

  Monitor Closely (1)siponimod and melphalan both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• meningococcal A C Y and W-135 diphtheria conjugate vaccine

  Serious - Use Alternative (1)siponimod decreases effects of meningococcal A C Y and W-135 diphtheria conjugate vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• meningococcal A C Y and W-135 polysaccharide vaccine combined

  Serious - Use Alternative (1)siponimod decreases effects of meningococcal A C Y and W-135 polysaccharide vaccine combined by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• meningococcal group B vaccine

  Serious - Use Alternative (1)siponimod decreases effects of meningococcal group B vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• mercaptopurine

  Monitor Closely (1)siponimod and mercaptopurine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• methadone

  Serious - Use Alternative (1)siponimod and methadone both increase QTc interval. Avoid or Use Alternate Drug.

• methotrexate

  Monitor Closely (1)siponimod and methotrexate both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• methyltestosterone

  Monitor Closely (1)siponimod and methyltestosterone both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• metoprolol

  Monitor Closely (1)siponimod, metoprolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• metronidazole

  Serious - Use Alternative (1)metronidazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• midostaurin

  Monitor Closely (1)siponimod and midostaurin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and midostaurin both increase QTc interval. Avoid or Use Alternate Drug.

• mifepristone

  Serious - Use Alternative (2)mifepristone will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and mifepristone both increase QTc interval. Avoid or Use Alternate Drug.

• mirtazapine

  Serious - Use Alternative (1)mirtazapine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• mitomycin

  Monitor Closely (1)siponimod and mitomycin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• mitotane

  Monitor Closely (1)siponimod and mitotane both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)mitotane will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• mitoxantrone

  Monitor Closely (1)siponimod and mitoxantrone both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• mobocertinib

  Serious - Use Alternative (1)siponimod and mobocertinib both increase QTc interval. Avoid or Use Alternate Drug.

• mogamulizumab

  Monitor Closely (1)siponimod and mogamulizumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• moxetumomab pasudotox

  Monitor Closely (1)siponimod and moxetumomab pasudotox both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• moxifloxacin

  Serious - Use Alternative (1)siponimod and moxifloxacin both increase QTc interval. Avoid or Use Alternate Drug.

• muromonab CD3

  Monitor Closely (1)siponimod and muromonab CD3 both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• mycophenolate

  Monitor Closely (1)siponimod and mycophenolate both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• nadolol

  Monitor Closely (1)siponimod, nadolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• nafcillin

  Serious - Use Alternative (1)nafcillin will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• nebivolol

  Monitor Closely (1)siponimod, nebivolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• necitumumab

  Monitor Closely (1)siponimod and necitumumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• nefazodone

  Serious - Use Alternative (1)nefazodone will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• nelarabine

  Monitor Closely (1)siponimod and nelarabine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• nelfinavir

  Serious - Use Alternative (1)nelfinavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• neratinib

  Monitor Closely (1)siponimod and neratinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• netupitant/palonosetron

  Serious - Use Alternative (1)netupitant/palonosetron will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• nicardipine

  Serious - Use Alternative (1)nicardipine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• nilotinib

  Monitor Closely (1)siponimod and nilotinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and nilotinib both increase QTc interval. Avoid or Use Alternate Drug.

• nilutamide

  Monitor Closely (1)siponimod and nilutamide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• niraparib

  Monitor Closely (1)siponimod and niraparib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• nitisinone

  Serious - Use Alternative (1)nitisinone will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• nivolumab

  Monitor Closely (1)siponimod and nivolumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• obinutuzumab

  Monitor Closely (1)siponimod and obinutuzumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• octreotide

  Serious - Use Alternative (1)siponimod and octreotide both increase QTc interval. Avoid or Use Alternate Drug.

• ofatumumab

  Monitor Closely (1)siponimod and ofatumumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ofatumumab SC

  Monitor Closely (1)ofatumumab SC, siponimod. Either increases effects of the other by immunosuppressive effects; risk of infection. Use Caution/Monitor. Consider the risk of additive immune system effects when coadministering immunosuppressive therapies with coadministration. When switching from therapies with immune effects, take into account the duration and mechanism of action of these therapies when initiating ofatumumab SC.

• ofloxacin

  Serious - Use Alternative (1)siponimod and ofloxacin both increase QTc interval. Avoid or Use Alternate Drug.

• olanzapine

  Serious - Use Alternative (2)olanzapine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  olanzapine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• olaparib

  Monitor Closely (1)siponimod and olaparib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• olaratumab

  Monitor Closely (1)siponimod and olaratumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• omacetaxine

  Monitor Closely (1)siponimod and omacetaxine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• omeprazole

  Serious - Use Alternative (1)omeprazole will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• ondansetron

  Serious - Use Alternative (1)siponimod and ondansetron both increase QTc interval. Avoid or Use Alternate Drug.

• osilodrostat

  Monitor Closely (1)osilodrostat and siponimod both increase QTc interval. Use Caution/Monitor.

• osimertinib

  Monitor Closely (1)siponimod and osimertinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and osimertinib both increase QTc interval. Avoid or Use Alternate Drug.

• oxaliplatin

  Monitor Closely (1)siponimod and oxaliplatin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)oxaliplatin and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• ozanimod

  Monitor Closely (1)ozanimod, siponimod. Either increases effects of the other by immunosuppressive effects; risk of infection. Use Caution/Monitor. Coadministration with immunosuppressive therapies may increase the risk of additive immune effects during therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs in order to avoid unintended additive immunosuppressive effects.

• paclitaxel

  Monitor Closely (1)siponimod and paclitaxel both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• paclitaxel protein bound

  Monitor Closely (1)siponimod and paclitaxel protein bound both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• pacritinib

  Monitor Closely (1)siponimod and pacritinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• palbociclib

  Monitor Closely (1)siponimod and palbociclib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• palifermin

  Monitor Closely (1)siponimod and palifermin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• paliperidone

  Serious - Use Alternative (1)siponimod and paliperidone both increase QTc interval. Avoid or Use Alternate Drug.

• panitumumab

  Monitor Closely (1)siponimod and panitumumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• panobinostat

  Monitor Closely (1)siponimod and panobinostat both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and panobinostat both increase QTc interval. Avoid or Use Alternate Drug.

• pasireotide

  Serious - Use Alternative (1)siponimod and pasireotide both increase QTc interval. Avoid or Use Alternate Drug.

• pazopanib

  Monitor Closely (1)siponimod and pazopanib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and pazopanib both increase QTc interval. Avoid or Use Alternate Drug.

• pegaspargase

  Monitor Closely (1)siponimod and pegaspargase both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• peginterferon beta-1a

  Monitor Closely (1)siponimod and peginterferon beta-1a both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immune effects during such therapy and in the weeks following administration. Siponimod can generally be started immediately after discontinuation of beta interferon.

• pegloticase

  Monitor Closely (1)siponimod and pegloticase both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• pembrolizumab

  Monitor Closely (1)siponimod and pembrolizumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• pemetrexed

  Monitor Closely (1)siponimod and pemetrexed both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• penbutolol

  Monitor Closely (1)siponimod, penbutolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• pentamidine

  Serious - Use Alternative (1)siponimod and pentamidine both increase QTc interval. Avoid or Use Alternate Drug.

• pentobarbital

  Serious - Use Alternative (1)pentobarbital will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• pentostatin

  Monitor Closely (1)siponimod and pentostatin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• perphenazine

  Monitor Closely (1)siponimod and perphenazine both increase QTc interval. Use Caution/Monitor.

• pertuzumab

  Monitor Closely (1)siponimod and pertuzumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• pexidartinib

  Monitor Closely (1)siponimod and pexidartinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• phenobarbital

  Serious - Use Alternative (1)phenobarbital will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• phenytoin

  Serious - Use Alternative (1)phenytoin will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• pimavanserin

  Serious - Use Alternative (1)siponimod and pimavanserin both increase QTc interval. Avoid or Use Alternate Drug.

• pimozide

  Serious - Use Alternative (1)siponimod and pimozide both increase QTc interval. Contraindicated.

• pindolol

  Monitor Closely (1)siponimod, pindolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• piroxicam

  Serious - Use Alternative (1)piroxicam will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• pitolisant

  Serious - Use Alternative (1)siponimod and pitolisant both increase QTc interval. Avoid or Use Alternate Drug.

• pneumococcal vaccine 13-valent

  Serious - Use Alternative (1)siponimod decreases effects of pneumococcal vaccine 13-valent by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• pneumococcal vaccine heptavalent

  Serious - Use Alternative (1)siponimod decreases effects of pneumococcal vaccine heptavalent by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• pneumococcal vaccine polyvalent

  Serious - Use Alternative (1)siponimod decreases effects of pneumococcal vaccine polyvalent by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• polatuzumab vedotin

  Monitor Closely (1)siponimod and polatuzumab vedotin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• poliovirus vaccine inactivated

  Serious - Use Alternative (1)siponimod decreases effects of poliovirus vaccine inactivated by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• pomalidomide

  Monitor Closely (1)siponimod and pomalidomide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ponatinib

  Monitor Closely (1)siponimod and ponatinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ponesimod

  Serious - Use Alternative (1)ponesimod, siponimod. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Consult cardiologist if considering treatment. Coadministration of ponesimod with drugs that decrease HR may have additive effects on decreasing HR and should generally not be initiated in these patients.

• porfimer

  Monitor Closely (1)siponimod and porfimer both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• posaconazole

  Serious - Use Alternative (2)posaconazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and posaconazole both increase QTc interval. Avoid or Use Alternate Drug.

• pralatrexate

  Monitor Closely (1)siponimod and pralatrexate both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• primaquine

  Serious - Use Alternative (1)primaquine and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• primidone

  Serious - Use Alternative (1)primidone will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• procainamide

  Serious - Use Alternative (1)siponimod, procainamide. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• procarbazine

  Monitor Closely (1)siponimod and procarbazine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• prochlorperazine

  Monitor Closely (1)siponimod and prochlorperazine both decrease QTc interval. Use Caution/Monitor.

• promethazine

  Serious - Use Alternative (1)siponimod and promethazine both decrease QTc interval. Avoid or Use Alternate Drug.

• propafenone

  Serious - Use Alternative (1)siponimod and propafenone both increase QTc interval. Avoid or Use Alternate Drug.

• propranolol

  Monitor Closely (1)siponimod, propranolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• pyrimethamine

  Serious - Use Alternative (1)pyrimethamine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• quetiapine

  Serious - Use Alternative (1)siponimod and quetiapine both increase QTc interval. Avoid or Use Alternate Drug.

• quinidine

  Serious - Use Alternative (1)siponimod, quinidine. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• quinine

  Serious - Use Alternative (2)quinine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  siponimod and quinine both increase QTc interval. Avoid or Use Alternate Drug.

• quinupristin/dalfopristin

  Serious - Use Alternative (1)quinupristin/dalfopristin will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• quizartinib

  Monitor Closely (1)siponimod and quizartinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• rabies vaccine

  Serious - Use Alternative (1)siponimod decreases effects of rabies vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• rabies vaccine chick embryo cell derived

  Serious - Use Alternative (1)siponimod decreases effects of rabies vaccine chick embryo cell derived by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• radium-223 dichloride

  Monitor Closely (1)siponimod and radium-223 dichloride both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ramucirumab

  Monitor Closely (1)siponimod and ramucirumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ranolazine

  Serious - Use Alternative (1)siponimod and ranolazine both increase QTc interval. Avoid or Use Alternate Drug.

• rasburicase

  Monitor Closely (1)siponimod and rasburicase both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• regorafenib

  Monitor Closely (1)siponimod and regorafenib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ribociclib

  Monitor Closely (1)siponimod and ribociclib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (2)ribociclib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and ribociclib both increase QTc interval. Avoid or Use Alternate Drug.

• rifabutin

  Serious - Use Alternative (1)rifabutin will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• rifampin

  Serious - Use Alternative (1)rifampin will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• rifapentine

  Serious - Use Alternative (1)rifapentine will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• rilonacept

  Monitor Closely (1)siponimod and rilonacept both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• rilpivirine

  Serious - Use Alternative (1)siponimod and rilpivirine both increase QTc interval. Avoid or Use Alternate Drug.

• risperidone

  Serious - Use Alternative (1)siponimod and risperidone both increase QTc interval. Avoid or Use Alternate Drug.

• ritonavir

  Serious - Use Alternative (1)ritonavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• rituximab

  Monitor Closely (1)siponimod and rituximab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• rituximab-hyaluronidase

  Monitor Closely (1)siponimod and rituximab-hyaluronidase both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• romidepsin

  Monitor Closely (1)siponimod and romidepsin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and romidepsin both increase QTc interval. Avoid or Use Alternate Drug.

• rotavirus oral vaccine, live

  Serious - Use Alternative (1)siponimod decreases effects of rotavirus oral vaccine, live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• rubella vaccine

  Serious - Use Alternative (1)siponimod decreases effects of rubella vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• rucaparib

  Monitor Closely (1)siponimod and rucaparib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• ruxolitinib

  Monitor Closely (1)siponimod and ruxolitinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• sacituzumab govitecan

  Monitor Closely (1)siponimod and sacituzumab govitecan both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• samarium sm 153 lexidronam

  Monitor Closely (1)siponimod and samarium sm 153 lexidronam both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• saquinavir

  Contraindicated (1)siponimod and saquinavir both increase QTc interval. Contraindicated.Serious - Use Alternative (1)saquinavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• schisandra

  Serious - Use Alternative (1)schisandra will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• secobarbital

  Serious - Use Alternative (1)secobarbital will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• selpercatinib

  Serious - Use Alternative (1)siponimod and selpercatinib both increase QTc interval. Avoid or Use Alternate Drug.

• sertraline

  Serious - Use Alternative (3)sertraline will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  sertraline and siponimod both increase QTc interval. Avoid or Use Alternate Drug.
  
  siponimod and sertraline both increase QTc interval. Avoid or Use Alternate Drug.

• sevoflurane

  Serious - Use Alternative (1)sevoflurane and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• siltuximab

  Monitor Closely (1)siponimod and siltuximab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• sipuleucel-T

  Monitor Closely (1)siponimod decreases effects of sipuleucel-T by pharmacodynamic antagonism. Modify Therapy/Monitor Closely.

• sirolimus

  Monitor Closely (1)siponimod and sirolimus both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• sirolimus intravitreal

  Monitor Closely (1)siponimod and sirolimus intravitreal both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• sirukumab

  Monitor Closely (1)siponimod and sirukumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• smallpox (vaccinia) and monkeypox vaccine, live, nonreplicating

  Serious - Use Alternative (2)siponimod decreases effects of smallpox (vaccinia) vaccine, attenuated by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.
  
  siponimod decreases effects of smallpox (vaccinia) vaccine, attenuated by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• smallpox (vaccinia) vaccine, live

  Serious - Use Alternative (1)siponimod decreases effects of smallpox (vaccinia) vaccine, live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• sodium iodide I-131

  Monitor Closely (1)siponimod and sodium iodide I-131 both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• solifenacin

  Serious - Use Alternative (2)siponimod and solifenacin both increase QTc interval. Avoid or Use Alternate Drug.
  
  solifenacin and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• sonidegib

  Monitor Closely (1)siponimod and sonidegib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• sorafenib

  Monitor Closely (1)siponimod and sorafenib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (2)sorafenib will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  siponimod and sorafenib both increase QTc interval. Avoid or Use Alternate Drug.

• sotalol

  Monitor Closely (1)siponimod, sotalol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.Serious - Use Alternative (1)siponimod, sotalol. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.

• sparsentan

  Monitor Closely (1)sparsentan will decrease the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. Sparsentan (a CYP2C9 inducer) decreases exposure of CYP2C9 substrates and reduces efficacy related to these substrates.

• St John's Wort

  Serious - Use Alternative (1)St John's Wort will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• streptozocin

  Monitor Closely (1)siponimod and streptozocin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• strontium 89 chloride

  Monitor Closely (1)siponimod and strontium 89 chloride both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• sulfadiazine

  Serious - Use Alternative (1)sulfadiazine will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• sulfamethoxazole

  Serious - Use Alternative (1)sulfamethoxazole will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• sunitinib

  Monitor Closely (1)siponimod and sunitinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (2)siponimod and sunitinib both increase QTc interval. Avoid or Use Alternate Drug.
  
  sunitinib and siponimod both increase QTc interval. Avoid or Use Alternate Drug.

• tacrolimus

  Monitor Closely (1)siponimod and tacrolimus both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and tacrolimus both increase QTc interval. Avoid or Use Alternate Drug.

• tagraxofusp

  Monitor Closely (1)siponimod and tagraxofusp both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• talazoparib

  Monitor Closely (1)siponimod and talazoparib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• tamoxifen

  Monitor Closely (1)siponimod and tamoxifen both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• tazemetostat

  Monitor Closely (2)siponimod and tazemetostat both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.
  
  tazemetostat will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• technetium Tc 99m tilmanocept

  Monitor Closely (1)siponimod and technetium Tc 99m tilmanocept both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• telavancin

  Serious - Use Alternative (1)siponimod and telavancin both increase QTc interval. Avoid or Use Alternate Drug.

• telotristat ethyl

  Serious - Use Alternative (1)telotristat ethyl will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

• temozolomide

  Monitor Closely (1)siponimod and temozolomide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• temsirolimus

  Monitor Closely (1)siponimod and temsirolimus both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• teniposide

  Monitor Closely (1)siponimod and teniposide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• tetanus & reduced diphtheria toxoids/ acellular pertussis vaccine

  Serious - Use Alternative (1)siponimod decreases effects of tetanus & reduced diphtheria toxoids/ acellular pertussis vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• tetanus toxoid adsorbed or fluid

  Serious - Use Alternative (1)siponimod decreases effects of tetanus toxoid adsorbed or fluid by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• tetrabenazine

  Serious - Use Alternative (1)siponimod and tetrabenazine both increase QTc interval. Avoid or Use Alternate Drug.

• tetracycline

  Serious - Use Alternative (1)tetracycline will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• thalidomide

  Monitor Closely (1)siponimod and thalidomide both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• thioguanine

  Monitor Closely (1)siponimod and thioguanine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• thioridazine

  Contraindicated (1)siponimod and thioridazine both increase QTc interval. Contraindicated.

• thiotepa

  Monitor Closely (1)siponimod and thiotepa both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• timolol

  Monitor Closely (1)siponimod, timolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• tipranavir

  Serious - Use Alternative (1)tipranavir will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• tivozanib

  Monitor Closely (1)siponimod and tivozanib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• tocilizumab

  Monitor Closely (1)siponimod and tocilizumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• tofacitinib

  Monitor Closely (1)siponimod and tofacitinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• tolbutamide

  Serious - Use Alternative (1)tolbutamide will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• topotecan

  Monitor Closely (1)siponimod and topotecan both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• toremifene

  Monitor Closely (1)siponimod and toremifene both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

• tositumomab

  Monitor Closely (1)siponimod and tositumomab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• trabectedin

  Monitor Closely (1)siponimod and trabectedin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• trametinib

  Monitor Closely (1)siponimod and trametinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• trastuzumab

  Monitor Closely (1)siponimod and trastuzumab both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• trastuzumab deruxtecan

  Monitor Closely (1)siponimod and trastuzumab deruxtecan both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• trazodone

  Serious - Use Alternative (1)siponimod and trazodone both increase QTc interval. Avoid or Use Alternate Drug.

• tretinoin

  Monitor Closely (1)siponimod and tretinoin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• triclabendazole

  Serious - Use Alternative (1)siponimod and triclabendazole both increase QTc interval. Avoid or Use Alternate Drug.

• trifluoperazine

  Monitor Closely (1)siponimod and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• trifluridine/tipiracil

  Monitor Closely (1)siponimod and trifluridine/tipiracil both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• trimethoprim

  Serious - Use Alternative (1)trimethoprim will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• triptorelin

  Monitor Closely (1)siponimod and triptorelin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and triptorelin both increase QTc interval. Avoid or Use Alternate Drug.

• tucatinib

  Serious - Use Alternative (1)tucatinib will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.

• tumor necrosis factor-alpha (TNF-alpha) adenovector

  Monitor Closely (1)siponimod and tumor necrosis factor-alpha (TNF-alpha) adenovector both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• typhoid polysaccharide vaccine

  Serious - Use Alternative (1)siponimod decreases effects of typhoid polysaccharide vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• typhoid vaccine live

  Serious - Use Alternative (1)siponimod decreases effects of typhoid vaccine live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• upadacitinib

  Serious - Use Alternative (1)siponimod, upadacitinib. Either increases effects of the other by immunosuppressive effects; risk of infection. Contraindicated.

• valbenazine

  Monitor Closely (1)valbenazine and siponimod both increase QTc interval. Use Caution/Monitor.

• valrubicin

  Monitor Closely (1)siponimod and valrubicin both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• vandetanib

  Monitor Closely (1)siponimod and vandetanib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and vandetanib both increase QTc interval. Avoid or Use Alternate Drug.

• vardenafil

  Serious - Use Alternative (1)siponimod and vardenafil both increase QTc interval. Avoid or Use Alternate Drug.

• varicella virus vaccine live

  Serious - Use Alternative (1)siponimod decreases effects of varicella virus vaccine live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• vemurafenib

  Monitor Closely (1)siponimod and vemurafenib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and vemurafenib both increase QTc interval. Avoid or Use Alternate Drug.

• venetoclax

  Monitor Closely (1)siponimod and venetoclax both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• venlafaxine

  Serious - Use Alternative (1)siponimod and venlafaxine both decrease QTc interval. Avoid or Use Alternate Drug.

• verapamil

  Serious - Use Alternative (2)siponimod, verapamil. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Because of the potential additive effects on heart rate, siponimod should generally not be initiated in patients taking QT prolonging drugs with known arrhythmogenic properties, heart rate lowering calcium channel blockers, or other drugs that may decrease heart rate. If treatment considered, obtain cardiology consult regarding switching to non-heart-rate lowering drugs or appropriate monitoring for treatment initiation.
  
  verapamil will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.

• vinblastine

  Monitor Closely (1)siponimod and vinblastine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• vincristine

  Monitor Closely (1)siponimod and vincristine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• vincristine liposomal

  Monitor Closely (1)siponimod and vincristine liposomal both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• vinorelbine

  Monitor Closely (1)siponimod and vinorelbine both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• vismodegib

  Monitor Closely (1)siponimod and vismodegib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• voclosporin

  Serious - Use Alternative (1)siponimod and voclosporin both increase QTc interval. Avoid or Use Alternate Drug.

• voriconazole

  Serious - Use Alternative (3)voriconazole will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.
  
  voriconazole will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a moderate or strong CYP3A4 inhibitor PLUS a moderate or strong CYP2C9 inhibitor is not recommended.
  
  siponimod and voriconazole both increase QTc interval. Avoid or Use Alternate Drug.

• vorinostat

  Monitor Closely (1)siponimod and vorinostat both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.Serious - Use Alternative (1)siponimod and vorinostat both increase QTc interval. Avoid or Use Alternate Drug.

• voxelotor

  Serious - Use Alternative (1)voxelotor will increase the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.

• yellow fever vaccine

  Serious - Use Alternative (1)siponimod decreases effects of yellow fever vaccine by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• zafirlukast

  Serious - Use Alternative (1)zafirlukast will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• ziprasidone

  Serious - Use Alternative (1)siponimod and ziprasidone both increase QTc interval. Avoid or Use Alternate Drug.

• ziv-aflibercept

  Monitor Closely (1)siponimod and ziv-aflibercept both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

• zoster vaccine live

  Serious - Use Alternative (1)siponimod decreases effects of zoster vaccine live by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.

• zoster vaccine recombinant

  Serious - Use Alternative (1)siponimod decreases effects of zoster vaccine recombinant by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Pause vaccinations beginning 1 week before initiating siponimod and for 4 weeks after stopping treatment. Coadministration with live attenuated vaccines may increase infection risk.