saquinavir (Rx)

HIV Infection

1000 mg (with ritonavir 100 mg) PO q12hr, or in combination with ritonavir-enhanced lopinavir

Treatment-naïve patients

• Initial dose: 500 mg PO BID plus ritonavir 100 mg BID x 7 days, THEN increase to 1000mg/100mg PO BID
• This gradual increase is due to potential for increased risk of PR and QT interval prolongation with standard 1000/100-mg BID dose
• Patients with a baseline QT interval <450 msec, an on-treatment ECG is recommended after ~10 days of therapy
• Patients with a QT interval prolongation over pretreatment by >20 msec should discontinue saquinavir/ritonavir therapy

HIV Infection

Indicated in combination with ritonavir and other antiretrovirals (ARTs) for treatment of HIV-1 infection

<16 years: Safety and efficacy not established

≥16 years: 1000 mg (plus ritonavir 100 mg) PO q12hr

For patients already taking ritonavir 100 mg BID as part of their ART regimen, no additional ritonavir is needed

Treatment-naïve patients

• Initial dose: 500 mg PO BID plus ritonavir 100 mg BID x 7 days, THEN increase to 1000mg/100mg PO BID
• This gradual increase is due to potential for increased risk of PR and QT interval prolongation with standard 1000/100-mg BID dose
• Patients with a baseline QT interval <450 msec, an on-treatment ECG is recommended after ~10 days of therapy
• Patients with a QT interval prolongation over pretreatment by >20 msec should discontinue saquinavir/ritonavir therapy

Investigational in treatment-experienced children

• <2 years: Safety and efficacy not established
• ≥2 years, 5 to <15 kg: 50 mg/kg (plus ritonavir 3 mg/kg) PO q12hr  
• ≥2 years, 15-40 kg: 50 mg/kg (plus ritonavir 2.5 mg/kg) PO q12hr
• ≥2 years, ≥40 kg: 50 mg/kg (plus ritonavir 100mg) PO q12hr

Contraindicated (60)

• albuterol

  saquinavir, albuterol. Either increases toxicity of the other by pharmacodynamic synergism. Contraindicated. Contraindicated. Saquinavir boosted with ritonavir increases risk of hypokalemia, QT prolongation, and cardiac arrhythmias.

• alfuzosin

  saquinavir increases levels of alfuzosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Potential for increased toxicity. .
  
  alfuzosin and saquinavir both increase QTc interval. Contraindicated.

• amiodarone

  amiodarone will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Contraindicated.

• artemether

  artemether and saquinavir both increase QTc interval. Contraindicated.

• astemizole

  saquinavir will increase the level or effect of astemizole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• atazanavir

  saquinavir will increase the level or effect of atazanavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• ceritinib

  ceritinib and saquinavir both increase QTc interval. Contraindicated.

• chloroquine

  chloroquine increases toxicity of saquinavir by QTc interval. Contraindicated.

• clarithromycin

  clarithromycin and saquinavir both increase QTc interval. Contraindicated.

• clozapine

  clozapine and saquinavir both increase QTc interval. Contraindicated.

• cobimetinib

  saquinavir will increase the level or effect of cobimetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Avoid coadministration with strong CYP3A4 inhibitors with (increases cobimetinib systemic exposure by 6.7-fold).

• conivaptan

  saquinavir will increase the level or effect of conivaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of conivaptan with strong CYP3A4 inhibitors is contraindicated.

• crizotinib

  crizotinib and saquinavir both increase QTc interval. Contraindicated.

• dasatinib

  saquinavir will increase the level or effect of dasatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
  
  dasatinib and saquinavir both increase QTc interval. Contraindicated.

• dihydroergotamine

  saquinavir increases levels of dihydroergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• dihydroergotamine intranasal

  saquinavir increases levels of dihydroergotamine intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• dofetilide

  dofetilide increases toxicity of saquinavir by QTc interval. Contraindicated.

• dronedarone

  saquinavir will increase the level or effect of dronedarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• elbasvir/grazoprevir

  saquinavir increases levels of elbasvir/grazoprevir by Other (see comment). Contraindicated. Comment: Coadministration with strong OATP1B1/3 inhibitors may increase the risk of ALT elevations owing to a significant increase in grazoprevir plasma concentrations.

• eletriptan

  saquinavir increases levels of eletriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Potential for increased toxicity. Contraindicated for use within 72 hours of potent CYP3A4 inhibitors.

• eliglustat

  saquinavir will increase the level or effect of eliglustat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inhibitors are contraindicated with eliglustat poor or intermediate metabolizers; reduce eliglustat dose from 84 mg BID to 84 mg once daily in extensive metabolizers; eliglustat is contraindiated if strong or moderate CYP2D6 inhibitors are given concomitantly with strong or moderate CYP3A inhibitors

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  saquinavir, elvitegravir/cobicistat/emtricitabine/tenofovir DF. Other (see comment). Contraindicated. Comment: Elvitegravir/cobicistat/emtricitabine/tenofovir is a complete regimen for HIV and should not be administered with other antiretrovirals.
  
  saquinavir will increase the level or effect of elvitegravir/cobicistat/emtricitabine/tenofovir DF by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• eplerenone

  saquinavir increases levels of eplerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Potential for increased toxicity. .

• ergoloid mesylates

  saquinavir will increase the level or effect of ergoloid mesylates by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• ergonovine

  saquinavir will increase the level or effect of ergonovine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• erythromycin base

  saquinavir will increase the level or effect of erythromycin base by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• erythromycin ethylsuccinate

  saquinavir will increase the level or effect of erythromycin ethylsuccinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• erythromycin lactobionate

  saquinavir will increase the level or effect of erythromycin lactobionate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• erythromycin stearate

  saquinavir will increase the level or effect of erythromycin stearate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• finerenone

  saquinavir will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• flibanserin

  saquinavir will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of flibanserin with moderate or strong CYP3A4 inhibitors is contraindicated. Severe hypotension or syncope can occur.

• gadobenate

  gadobenate and saquinavir both increase QTc interval. Contraindicated.

• gilteritinib

  gilteritinib and saquinavir both increase QTc interval. Contraindicated.

• isavuconazonium sulfate

  saquinavir will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• ivabradine

  saquinavir will increase the level or effect of ivabradine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of ivabradine with strong CYP3A4 inhibitors is contraindicated.

• lefamulin

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

• lomitapide

  saquinavir increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Increases lomitapide levels several folds.

• lonafarnib

  saquinavir will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Lonafarnib is a sensitive CYP3A4 substrate. Coadministration with strong or moderate CYP3A4 inhibitors is contraindicated.

• lovastatin

  lovastatin will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Contraindicated.
  
  saquinavir increases levels of lovastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inhibitors increase systemic statin exposure and risk of myopathy, including rhabdomyolysis.

• lurasidone

  saquinavir increases levels of lurasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of lurasidone and strong CYP3A4 inhibitors is contraindicated.

• mavacamten

  saquinavir will increase the level or effect of mavacamten by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inhibitors may increase mavacamten systemic exposure, resulting in heart failure due to systolic dysfunction.

• naloxegol

  saquinavir will increase the level or effect of naloxegol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of naloxegol with strong CYP3A4 inhibitors can significantly increase naloxegol systemic exposure which may precipitate opioid withdrawal symptoms

• pacritinib

  saquinavir will increase the level or effect of pacritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• quinidine

  saquinavir will increase the level or effect of quinidine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• regorafenib

  saquinavir, regorafenib. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inhibitors increase regorafenib levels and decrease exposure of the active metabolites M-2 and M-5.

• ribociclib

  ribociclib increases toxicity of saquinavir by QTc interval. Contraindicated.

• rifampin

  rifampin will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Contraindicated. May result in loss of antiviral efficacy and/or development of viral resistance.
  
  rifampin increases toxicity of saquinavir by unspecified interaction mechanism. Contraindicated. Adding rifampin to saquinavir/ritonaivr (ritonavir boosted saquinavir) may result in toxic hepatitis.

• simvastatin

  simvastatin will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Contraindicated.
  
  saquinavir increases levels of simvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Contraindicated. Increased risk for rhabdomyolysis with drugs that increase simvastatin systemic exposure.
  
  saquinavir increases toxicity of simvastatin by Other (see comment). Contraindicated. Comment: OATP1B1 inhibitors may increase risk of myopathy.

• siponimod

  siponimod and saquinavir both increase QTc interval. Contraindicated.

• sorafenib

  saquinavir will increase the level or effect of sorafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• St John's Wort

  St John's Wort will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• sunitinib

  sunitinib and saquinavir both increase QTc interval. Contraindicated.

• tacrolimus

  saquinavir will increase the level or effect of tacrolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
  
  tacrolimus and saquinavir both increase QTc interval. Contraindicated.

• tipranavir

  saquinavir will increase the level or effect of tipranavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
  
  tipranavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• trazodone

  trazodone will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Contraindicated.
  
  saquinavir will increase the level or effect of trazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• triazolam

  saquinavir will increase the level or effect of triazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• vemurafenib

  saquinavir will increase the level or effect of vemurafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• venetoclax

  saquinavir will increase the level or effect of venetoclax by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Use of strong CYP3A4 inhibitors is contraindicated with venetoclax during the initial ramp-up dosing phase. If a strong CYP3A inhibitor must be used after the ramp-up phase, reduce the venetoclax dose by at least 75%.

• voclosporin

  saquinavir will increase the level or effect of voclosporin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• ziprasidone

  ziprasidone increases toxicity of saquinavir by QTc interval. Contraindicated. Potential for serious and/or life threatening reactions such as cardiac arrhythmias.

Serious - Use Alternative (231)

• abametapir

  abametapir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.

• acalabrutinib

  saquinavir will increase the level or effect of acalabrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of acalabrutinib with strong CYP3A inhibitors. If a strong CYP3A inhibitor must be used short-term (eg, up to 7 days), temporarily interrupt treatment with acalabrutinib.

• acebutolol

  saquinavir, acebutolol. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of PR prolongation and cardiac arrhythmias.

• ado-trastuzumab emtansine

  saquinavir increases levels of ado-trastuzumab emtansine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. DM1, the cytotoxic component, is metabolized mainly by CYP3A4; strong CYP3A4 inhibitors may increase DM1 exposure and toxicity.

• afatinib

  saquinavir increases levels of afatinib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. Reduce afatinib daily dose by 10 mg if not tolerated when coadministered with P-gp inhibitors.

• almotriptan

  saquinavir increases levels of almotriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid use in patients with renal or hepatic impairment.

• alprazolam

  saquinavir increases levels of alprazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Avoid coadministration. If need to use, decrease alprazolam dose.

• amiodarone

  saquinavir will increase the level or effect of amiodarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• amisulpride

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

• anagrelide

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

• apalutamide

  apalutamide will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.

• apixaban

  saquinavir will increase the level or effect of apixaban by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If taking apixaban dose >2.5 mg BID, decrease dose by 50% if coadministered with strong dual inhibitors of CYP3A4 and P-gp; if currently taking apixaban 2.5 mg PO BID, avoid coadministration with strong dual inhibitors of CYP3A4 and P-gp

• apomorphine

  saquinavir, apomorphine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.
  
  apomorphine and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• aprepitant

  saquinavir will increase the level or effect of aprepitant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• aripiprazole

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

• arsenic trioxide

  saquinavir, arsenic trioxide. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.

• artemether

  saquinavir increases levels of artemether by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• artemether/lumefantrine

  saquinavir increases levels of artemether/lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• asenapine

  saquinavir, asenapine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.
  
  asenapine and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• asenapine transdermal

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

• atenolol

  saquinavir, atenolol. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of PR prolongation and cardiac arrhythmias.

• atomoxetine

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

• atorvastatin

  saquinavir will increase the level or effect of atorvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Limit atorvastatin dose to 20 mg/day
  
  saquinavir increases toxicity of atorvastatin by Other (see comment). Avoid or Use Alternate Drug. Comment: OATP1B1 inhibitors may increase risk of myopathy.

• avanafil

  saquinavir will increase the level or effect of avanafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. CYP3A4 inhibitors may reduce avanafil clearance increasing systemic exposure to avanafil; significantly increased levels may result in significant adverse events including severe hypotension, syncope, visual changes, and priapism. Coadministration with strong CYP3A4 is contraindicated.

• avapritinib

  saquinavir will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of avapritinib with strong CYP3A4 inhibitors.

• axitinib

  saquinavir increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, reduce axitinib dose by 50%.

• azithromycin

  saquinavir, azithromycin. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.

• bedaquiline

  saquinavir will increase the level or effect of bedaquiline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of bedaquiline with strong CYP3A4 inhibitors for >14 consecutive days, unless the benefit of treatment outweighs the risk

• betibeglogene autotemcel

  saquinavir, betibeglogene autotemcel. Other (see comment). Avoid or Use Alternate Drug. Comment: Do not take antiretroviral medications for at least 1 month before mobilization or expected duration for elimination of the medications, and until all cycles of apheresis are completed. Antiretroviral medications may interfere with manufacturing of apheresed cells.

• bosentan

  bosentan will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. stop bosentan >36 hours prior to PI initiation and restart 10 days after PI initiation at 62.5 mg once daily or every other day.

• bosutinib

  saquinavir increases levels of bosutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Strong CYP3A4 inhibitors increases bosutinib plasma concentration ~5-fold.
  
  saquinavir increases levels of bosutinib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• brigatinib

  saquinavir will increase the level or effect of brigatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If concomitant use of a strong CYP3A inhibitor cannot be avoided, reduce the brigatinib once daily dose by about 50% (ie, from 180 mg to 90 mg, or from 90 mg to 60 mg). After discontinuation of a strong CYP3A inhibitor, resume the brigatinib dose that was tolerated prior to initiating the strong CYP3A inhibitor.

• bromocriptine

  saquinavir will increase the level or effect of bromocriptine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• budesonide

  saquinavir will increase the level or effect of budesonide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• buprenorphine

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

• buprenorphine transdermal

  saquinavir will increase the level or effect of buprenorphine transdermal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• cabergoline

  saquinavir increases levels of cabergoline by decreasing metabolism. Contraindicated.

• cabotegravir

  saquinavir, cabotegravir. Other (see comment). Avoid or Use Alternate Drug. Comment: Cabotegravir plus rilpivirine is a complete regimen. Coadministration with other antiretroviral medications for treating HIV-1 infection is not recommended.

• cabozantinib

  saquinavir will increase the level or effect of cabozantinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of cabozantinib with strong CYP3A4 inhibitors. If a strong CYP3A4 inhibitor is required, decrease cabozantinib dose by 40 mg/day (Cometriq) or by 20 mg/day (Cabometyx). Resume previous dose 2-3 days after strong CYP3A4 inhibitor discontinued.

• carbamazepine

  carbamazepine will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ceritinib

  saquinavir increases levels of ceritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid if possible; if concomitant use is unavoidable, reduce ceritinib dose by ~33%; after discontinuation of strong CYP3A inhibitor, resume at previous dose.

• chloroquine

  saquinavir will increase the level or effect of chloroquine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ciclesonide inhaled

  saquinavir will increase the level or effect of ciclesonide inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• cilostazol

  saquinavir will increase the level or effect of cilostazol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• cimetidine

  cimetidine will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ciprofloxacin

  saquinavir increases levels of ciprofloxacin by pharmacodynamic synergism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• cisapride

  saquinavir increases levels of cisapride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Increased risk of QT prolongation and cardiac arrhythmias.

• citalopram

  saquinavir will increase the level or effect of citalopram by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• clarithromycin

  clarithromycin will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  saquinavir will increase the level or effect of clarithromycin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• clozapine

  saquinavir increases levels of clozapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• cobicistat

  cobicistat will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  cobicistat will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.
  
  saquinavir will increase the level or effect of cobicistat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• colchicine

  saquinavir will increase the level or effect of colchicine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid use of colchicine with strong CYP3A4 inhibitors. If coadministration is necessary, decrease colchicine dose or frequency as recommended in prescribing information. Use of any colchicine product in conjunction with strong CYP3A4 inhibitors is contraindicated in patients with renal or hepatic impairment.

• copanlisib

  saquinavir will increase the level or effect of copanlisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If concomitant use with strong CYP3A inhibitors cannot be avoided, reduce copanlisib dose to 45 mg.

• dabrafenib

  saquinavir increases levels of dabrafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  dabrafenib will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• dapsone

  saquinavir will increase the level or effect of dapsone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• daridorexant

  saquinavir will increase the level or effect of daridorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• darunavir

  saquinavir decreases levels of darunavir by increasing metabolism. Avoid or Use Alternate Drug.
  
  saquinavir will increase the level or effect of darunavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• degarelix

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

• delavirdine

  saquinavir will increase the level or effect of delavirdine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• desflurane

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

• dexamethasone

  saquinavir will increase the level or effect of dexamethasone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• disopyramide

  saquinavir increases levels of disopyramide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.

• doxorubicin

  saquinavir will increase the level or effect of doxorubicin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• doxorubicin liposomal

  saquinavir will increase the level or effect of doxorubicin liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• dronedarone

  dronedarone will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• droperidol

  saquinavir increases levels of droperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• edoxaban

  saquinavir will increase the level or effect of edoxaban by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. Dose adjustment may be required with strong P-gp inhibitors. DVT/PE treatment: Decrease dose to 30 mg PO once daily. NVAF: No dose reduction recommended

• efavirenz

  saquinavir will increase the level or effect of efavirenz by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  efavirenz and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• elbasvir/grazoprevir

  saquinavir will increase the level or effect of elbasvir/grazoprevir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• eliglustat

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

• eluxadoline

  saquinavir increases levels of eluxadoline by decreasing metabolism. Avoid or Use Alternate Drug. Decrease eluxadoline dose to 75 mg PO BID if coadministered with OATP1B1 inhibitors. .

• encorafenib

  saquinavir will increase the level or effect of encorafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If concomitant use of a strong CYP3A4 inhibitor is unavoidable, reduce encorafenib dose to one-third of the dose (eg, reduce from 450 mg/day to 150 mg/day). After discontinuing the inhibitor for 3-5 elimination half-lives, resume previous encorafenib dose.
  
  encorafenib and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• entrectinib

  saquinavir and entrectinib both increase QTc interval. Avoid or Use Alternate Drug.
  
  saquinavir will increase the level or effect of entrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of strong CYP3A4 inhibitors with entrectinib, a CYP3A4 substrate. If coadministration unavoidable, reduce entrectinib dose to 100 mg/day for patients aged 12 y or older with BSA >1.50m2. Resume previous entrectinib dose after discontinuing strong CYP3A inhibitor for 3-5 elimination half-lives.

• enzalutamide

  saquinavir will increase the level or effect of enzalutamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  enzalutamide will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erdafitinib

  saquinavir will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.
  
  erdafitinib will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

• ergoloid mesylates

  saquinavir increases levels of ergoloid mesylates by decreasing metabolism. Contraindicated.

• ergotamine

  saquinavir increases levels of ergotamine by decreasing metabolism. Contraindicated.
  
  saquinavir will increase the level or effect of ergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• eribulin

  eribulin and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. Potential for enhanced QTc-prolonging effects; if concurrent use is necessary then ECG monitoring is recommended.

• erlotinib

  saquinavir will increase the level or effect of erlotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin base

  erythromycin base will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin ethylsuccinate

  erythromycin ethylsuccinate will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin lactobionate

  erythromycin lactobionate will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin stearate

  erythromycin stearate will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• escitalopram

  escitalopram increases toxicity of saquinavir by QTc interval. Avoid or Use Alternate Drug.
  
  saquinavir will increase the level or effect of escitalopram by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ethinylestradiol

  saquinavir, ethinylestradiol. Other (see comment). Avoid or Use Alternate Drug. Comment: Significant changes (increase or decrease) can occur in estrogen plasma levels. Efficacy of hormonal contraceptives may be reduced. Use of a nonhormonal contraceptive is recommended. .
  
  saquinavir will increase the level or effect of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• everolimus

  saquinavir will increase the level or effect of everolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• fedratinib

  saquinavir will increase the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid fedratinib coadministration with strong CYP3A4 inhibitors, decrease fedratinib dose to 200 mg/day. If CYP3A4 inhibitor discontinued, increase fedratinib dose to 300 mg/day for 2 weeks, and then 400 mg/day thereafter as tolerated.
  
  saquinavir will increase the level or effect of fedratinib by Other (see comment). Avoid or Use Alternate Drug. Avoid coadministration of fedratinib (a CYP3A4 and CYP2C19 substrate) with dual CYP3A4 and CYP2C19 inhibitor. Effect of coadministration of a dual CYP3A4 and CYP2C19 inhibitor with fedratinib has not been studied.

• felbamate

  saquinavir will increase the level or effect of felbamate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• fentanyl

  saquinavir will increase the level or effect of fentanyl by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fentanyl intranasal

  saquinavir will increase the level or effect of fentanyl intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fentanyl transdermal

  saquinavir will increase the level or effect of fentanyl transdermal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fentanyl transmucosal

  saquinavir will increase the level or effect of fentanyl transmucosal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fexinidazole

  saquinavir will decrease the level or effect of fexinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration, monitor fexinidazole for decreased efficacy owing to decreased plasma concentrations of active M1 and M2 metabolites.
  
  fexinidazole and saquinavir 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 saquinavir 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 saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• fluphenazine

  saquinavir increases levels of fluphenazine by QTc interval. Avoid or Use Alternate Drug. Potential for increased toxicity. .

• fluticasone intranasal

  saquinavir will increase the level or effect of fluticasone intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Strong CYP3A4 inhibitors may increase systemic corticosteroid adverse effects; monitor for signs/symptoms of high corticosteroid concentrations including Cushing type signs/symptoms.

• gemifloxacin

  saquinavir increases levels of gemifloxacin by QTc interval. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.
  
  saquinavir increases levels of gemifloxacin by pharmacodynamic synergism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• gilteritinib

  saquinavir will increase the level or effect of gilteritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Consider alternatives to any strong CYP3A4 inhibitor when coadministered with gilteritinib. If such a combination cannot be avoided, closely monitor for gilteritinib-related adverse effects. Interrupt and reduce gilteritinib dosage in patients with serious or life-threatening toxicity.

• glasdegib

  saquinavir will increase the level or effect of glasdegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Consider alternate therapies that are not strong CYP3A inhibitors or monitor for increased risk of adverse effects, including QTc interval prolongation.
  
  saquinavir and glasdegib both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, monitor for increased risk of QTc interval prolongation.

• granisetron

  saquinavir increases levels of granisetron by QTc interval. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• haloperidol

  saquinavir increases levels of haloperidol by QTc interval. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.
  
  saquinavir increases levels of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• hydroxychloroquine sulfate

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

• hydroxyprogesterone caproate

  saquinavir will increase the level or effect of hydroxyprogesterone caproate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• hydroxyzine

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

• ibrutinib

  saquinavir increases levels of ibrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of ibrutinib and strong CYP3A4 inhibitors. If a strong CYP3A4 inhibitor must be used short-term (eg, anti-infectives for =7 days), interrupt ibrutinib therapy until strong CYP3A4 inhibitor is discontinued.

• idelalisib

  saquinavir will increase the level or effect of idelalisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministered with strong CYP3A inhibitors, monitor for signs of idelalisib toxicity; follow recommendations for dosage modifications if adverse reactions occur
  
  idelalisib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates

• indinavir

  saquinavir will increase the level or effect of indinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• infigratinib

  saquinavir will increase the level or effect of infigratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• inotuzumab

  inotuzumab and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. If unable to avoid concomitant use, obtain ECGs and electrolytes before and after initiation of any drug known to prolong QTc, and periodically monitor as clinically indicated during treatment.

• irinotecan

  saquinavir will increase the level or effect of irinotecan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• irinotecan liposomal

  saquinavir will increase the level or effect of irinotecan liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• isoflurane

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

• itraconazole

  saquinavir will increase the level or effect of itraconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  itraconazole and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• ivosidenib

  saquinavir will increase the level or effect of ivosidenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of strong CYP3A4 inhibitors with ivosidenib or replace with alternate therapies. If coadministration of a strong CYP3A4 inhibitor is unavoidable, reduce ivosidenib dose to 250 mg qDay. If the strong inhibitor is discontinued, increase ivosidenib dose (after at least 5 half-lives of the strong CYP3A4 inhibitor) to the recommended dose of 500 mg qDay. Monitor for increased risk of QTc interval prolongation.
  
  ivosidenib and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of QTc prolonging drugs with ivosidenib or replace with alternate therapies. If coadministration of a QTc prolonging drug is unavoidable, monitor for increased risk of QTc interval prolongation.
  
  ivosidenib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternative therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.

• ixabepilone

  saquinavir will increase the level or effect of ixabepilone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ketoconazole

  ketoconazole will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• lapatinib

  saquinavir will increase the level or effect of lapatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• larotrectinib

  saquinavir will increase the level or effect of larotrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of larotrectinib with strong CYP3A4 inhibitors is unavoidable, reduce larotrectinib dose by 50%. Resume prior larotrectinib dose once CYP3A4 inhibitor discontinued for 3-5 half-lives.

• lasmiditan

  lasmiditan increases levels of saquinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• lefamulin

  saquinavir will increase the level or effect of lefamulin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of lefamulin with strong CYP3A inhibitors.

• lemborexant

  saquinavir will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of lemborexant with moderate or strong CYP3A inhibitors.

• levofloxacin

  saquinavir increases levels of levofloxacin by QTc interval. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• levoketoconazole

  levoketoconazole will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• levonorgestrel oral/ethinylestradiol/ferrous bisglycinate

  saquinavir, levonorgestrel oral/ethinylestradiol/ferrous bisglycinate. Other (see comment). Avoid or Use Alternate Drug. Comment: Significant changes (increase or decrease) can occur in estrogen plasma levels. Efficacy of hormonal contraceptives may be reduced. Use of a nonhormonal contraceptive is recommended.

• lithium

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

• lopinavir

  saquinavir will increase the level or effect of lopinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• lorlatinib

  saquinavir will increase the level or effect of lorlatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministering lorlatinib with strong CYP3A inhibitors. If unavoidable, reduce lorlatinib dose by 25 mg/day. If strong CYP3A inhibitor discontinued, increase to previous lorlatinib (dose after 3 plasma half-lives of strong CYP3A inhibitor). See monograph for further details.
  
  lorlatinib will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• lumefantrine

  saquinavir increases levels of lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• lurbinectedin

  saquinavir will increase the level or effect of lurbinectedin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• macimorelin

  macimorelin and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. Macimorelin causes an increase of ~11 msec in the corrected QT interval. Avoid coadministration with drugs that prolong QT interval, which could increase risk for developing torsade de pointes-type ventricular tachycardia. Allow sufficient washout time of drugs that are known to prolong the QT interval before administering macimorelin.
  
  saquinavir will increase the level or effect of macimorelin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• macitentan

  saquinavir will increase the level or effect of macitentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministering macitentan with strong CYP3A4 inhibitors

• medroxyprogesterone

  saquinavir will increase the level or effect of medroxyprogesterone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• mefloquine

  saquinavir increases levels of mefloquine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Avoid coadministration during and for 15 weeks after discontinuing mefloquine. .

• mestranol

  saquinavir will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• methadone

  saquinavir, methadone. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Increased risk of PR prolongation and cardiac arrhythmias.
  
  saquinavir will increase the level or effect of methadone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• methylergonovine

  saquinavir increases levels of methylergonovine by decreasing metabolism. Contraindicated.
  
  saquinavir will increase the level or effect of methylergonovine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• midazolam

  saquinavir increases levels of midazolam by decreasing metabolism. Contraindicated.
  
  saquinavir will increase the level or effect of midazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• midazolam intranasal

  saquinavir will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of strong CYP3A4 inhibitors with midazolam intranasal causes higher midazolam systemic exposure, which may prolong sedation.

• midostaurin

  saquinavir will increase the level or effect of midostaurin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong CYP3A4 inhibitors cannot be avoided, monitor midostaurin for increased risk of adverse reactions, especially during the first week of treatment.

• mifepristone

  mifepristone will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• mobocertinib

  saquinavir will increase the level or effect of mobocertinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  mobocertinib and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, reduce mobocertinib dose and monitor QTc interval more frequently.

• moxifloxacin

  saquinavir increases levels of moxifloxacin by QTc interval. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• nefazodone

  saquinavir will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• nelfinavir

  saquinavir will increase the level or effect of nelfinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• neratinib

  saquinavir will increase the level or effect of neratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of neratinib with strong/moderate CYP3A4 inhibitors.

• nevirapine

  saquinavir will increase the level or effect of nevirapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• nilotinib

  saquinavir will increase the level or effect of nilotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• olanzapine

  olanzapine and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• olaparib

  saquinavir will increase the level or effect of olaparib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong CYP3A inhibitors cannot be avoided, reduce olaparib dose to 150 mg (capsule) or 100 mg (tablet) PO BID. Do not substitute tablets with capsules.

• ombitasvir/paritaprevir/ritonavir

  saquinavir will increase the level or effect of ombitasvir/paritaprevir/ritonavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC)

  saquinavir will increase the level or effect of ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ondansetron

  ondansetron and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.
  
  saquinavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• osimertinib

  saquinavir will increase the level or effect of osimertinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of osimertinib with strong CYP3A4 inhibitors. If no other alternative treatment exists, monitor patient more closely for adverse effects.

• oxaliplatin

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

• oxycodone

  saquinavir increases levels of oxycodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Oxycodone dose reduction may be warranted when coadministered with strong CYP3A4 inhibitors.

• palbociclib

  saquinavir will increase the level or effect of palbociclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of palbociclib with strong CYP3A inhibitors. If unable to avoid, reduce palbociclib dose to 75 mg/day.

• paliperidone

  saquinavir, paliperidone. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.

• panobinostat

  saquinavir and panobinostat both increase QTc interval. Avoid or Use Alternate Drug. Panobinostat is known to significantly prolong QT interval. Panobinostat prescribing information states use with drugs known to prolong QTc is not recommended.

• pazopanib

  saquinavir increases levels of pazopanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• pemigatinib

  saquinavir will increase the level or effect of pemigatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors is unavoidable, reduce pemigatinib dose (refer to drug monograph dosage modifications). After discontinuing the CYP3A4 inhibitor for 3 elimination half-lives, may resume previous pemigatinib dose.

• pentamidine

  saquinavir, pentamidine. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Increased risk of PR or QT prolongation and cardiac arrhythmias.

• perphenazine

  saquinavir, perphenazine. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Increased risk of PR or QT prolongation and cardiac arrhythmias.

• pexidartinib

  saquinavir will increase the level or effect of pexidartinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors is unavoidable, reduce pexidartinib dose (refer to drug monograph dosage modifications). After discontinuing the CYP3A4 inhibitor for 3 elimination half-lives, may resume previous pexidartinib dose.

• pimavanserin

  saquinavir will increase the level or effect of pimavanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Decrease dose to 17 mg/day if pimavanserin is coadministered with strong CYP3A4 inhibitors.

• pimozide

  saquinavir increases levels of pimozide by decreasing metabolism. Contraindicated. Risk of prolonged QTc interval.
  
  saquinavir will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• pitolisant

  saquinavir and pitolisant both increase QTc interval. Avoid or Use Alternate Drug.
  
  saquinavir will increase the level or effect of pitolisant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• pomalidomide

  saquinavir increases levels of pomalidomide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  saquinavir increases levels of pomalidomide by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• ponatinib

  saquinavir increases levels of ponatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Decrease ponatinib starting dose to 30 mg qDay if coadministration with strong CYP3A4 inhibitors cannot be avoided.

• pralsetinib

  saquinavir will increase the level or effect of pralsetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• primaquine

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

• procainamide

  saquinavir, procainamide. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Increased risk of PR or QT prolongation and cardiac arrhythmias.

• prochlorperazine

  saquinavir, prochlorperazine. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.

• quazepam

  saquinavir will increase the level or effect of quazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• quetiapine

  saquinavir will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• quinidine

  quinidine will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• quinine

  saquinavir will increase the level or effect of quinine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• ranolazine

  saquinavir will increase the level or effect of ranolazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• red yeast rice

  saquinavir will increase the level or effect of red yeast rice by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. May increase creatine kinase levels and increase risk of myopathy or rhabdomyolysis; red yeast rice contains monocolin K (reportedly identical to lovastatin)

• ribociclib

  saquinavir will increase the level or effect of ribociclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If a strong CYP3A inhibitor must be coadministered with ribociclib, reduce the ribociclib starting dose to 400 mg/day.
  
  ribociclib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• rifabutin

  saquinavir will decrease the level or effect of rifabutin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Dosage reduction of rifabutin by at least 75% of the usual dose of 300 mg/day is recommended (ie, a maximum dose of 150 mg every other day or 3 times/week). Increased monitoring for adverse events is warranted in patients receiving the combination. Consider monitoring rifabutin concentrations to ensure adequate exposure.
  
  rifabutin will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rifapentine

  rifapentine decreases levels of saquinavir by increasing metabolism. Contraindicated.

• rimegepant

  saquinavir will increase the level or effect of rimegepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  saquinavir will increase the level or effect of rimegepant by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• riociguat

  saquinavir will increase the level or effect of riociguat by decreasing metabolism. Avoid or Use Alternate Drug. Coadministration of riociguat (substrate of CYP isoenzymes 1A1, 2C8, 3A, 2J2) with strong CYP inhibitors may require a decreased initial dose of 0.5 mg PO TID; monitor for signs of hypotension and reduce dose if needed
  
  saquinavir will increase the level or effect of riociguat by Other (see comment). Avoid or Use Alternate Drug. Coadministration of riociguat (an ABCG2 [BCRP] substrate) with strong ABCG2 inhibitors may require a decreased initial dose of 0.5 mg PO TID; monitor for signs of hypotension and reduce dose if needed
  
  saquinavir will increase the level or effect of riociguat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ritonavir

  saquinavir will increase the level or effect of ritonavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• romidepsin

  saquinavir will increase the level or effect of romidepsin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with strong 3A4 inhibitors shoul d be avoided if possible.

• rosuvastatin

  saquinavir increases toxicity of rosuvastatin by Other (see comment). Avoid or Use Alternate Drug. Comment: OATP1B1 inhibitors may increase risk of myopathy.

• ruxolitinib

  saquinavir will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Reduce ruxolitinib starting dose to 10 mg BID with platelet count 100 X 10^9/L or more and concurrent use of strong CYP3A4 inhibitors; avoid with platelet counts <100 X 10^9/L

• ruxolitinib topical

  saquinavir will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Reduce ruxolitinib starting dose to 10 mg BID with platelet count 100 X 10^9/L or more and concurrent use of strong CYP3A4 inhibitors; avoid with platelet counts <100 X 10^9/L

• selpercatinib

  saquinavir will increase the level or effect of selpercatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• selumetinib

  saquinavir will increase the level or effect of selumetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors cannot be avoided, reduce selumetinib dosage (refer to selumetinib monograph for further information). After discontinuation of the strong or moderate CYP3A4 inhibitor for 3 elimination half-lives, resume selumetinib dose that was taken before initiating the inhibitor.

• sertraline

  sertraline and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• sevoflurane

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

• siponimod

  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.

• sirolimus

  saquinavir will increase the level or effect of sirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• solifenacin

  saquinavir increases levels of solifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of PR or QT prolongation and cardiac arrhythmias.
  
  solifenacin and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• sonidegib

  saquinavir will increase the level or effect of sonidegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sonidegib with strong CYP3A4 inhibitors.

• sotalol

  saquinavir, sotalol. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.

• sotorasib

  sotorasib will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If use is unavoidable, refer to the prescribing information of the P-gp substrate for dosage modifications.

• St John's Wort

  St John's Wort decreases levels of saquinavir by increasing metabolism. Contraindicated.

• sunitinib

  saquinavir increases levels of sunitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• suvorexant

  saquinavir increases levels of suvorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Suvorexant not recommended with use of strong CYP3A4 inhibitors.

• tamoxifen

  saquinavir, tamoxifen. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. CYP3A4 inhibition decreases metabolism of tamoxifen to N-desmethyl tamoxifen (active metabolite with similar biologic activity).

• tamsulosin

  saquinavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• tazemetostat

  saquinavir will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• telavancin

  saquinavir, telavancin. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug.

• temsirolimus

  saquinavir will increase the level or effect of temsirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• tepotinib

  saquinavir will increase the level or effect of tepotinib by Other (see comment). Avoid or Use Alternate Drug. Interaction not studied clinically. Metabolism and data suggest drugs that are strong CYP3A4 and P-gp inhibitors may increase tepotinib (a P-gp and CYP3A4 substrate) effects and risk of toxicities.
  
  tepotinib will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If concomitant use unavoidable, reduce the P-gp substrate dosage if recommended in its approved product labeling.

• tiagabine

  saquinavir will increase the level or effect of tiagabine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• tipranavir

  tipranavir decreases levels of saquinavir by unspecified interaction mechanism. Avoid or Use Alternate Drug.

• tofacitinib

  saquinavir increases levels of tofacitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Reduce tofacitinib dose to 5 mg qDay when coadministered with potent CYP3A4 inhibitors.

• tolterodine

  saquinavir will increase the level or effect of tolterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• tolvaptan

  saquinavir will increase the level or effect of tolvaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• topotecan

  saquinavir will increase the level or effect of topotecan by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. Product labeling for PO topotecan recommends avoiding concomitant use of P-gp inhibitors; the interaction with IV topotecan may be less severe but is still likely of clinical significance

• trabectedin

  saquinavir will increase the level or effect of trabectedin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If strong CYP3A inhibitor must be used, short-term (eg, less than 14 days), administer strong CYP3A inhibitor 1 week after trabectedin infusion, and discontinue the day prior to next trabectedin infusion

• triazolam

  saquinavir increases levels of triazolam by decreasing metabolism. Contraindicated.

• tucatinib

  tucatinib will increase the level or effect of saquinavir 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.

• ubrogepant

  saquinavir will increase the level or effect of ubrogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• umeclidinium bromide/vilanterol inhaled

  saquinavir increases toxicity of umeclidinium bromide/vilanterol inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

• vandetanib

  saquinavir, vandetanib. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Avoid coadministration with drugs known to prolong QT interval; if a drug known to prolong QT interval must be used, more frequent ECG monitoring is recommended.
  
  saquinavir will increase the level or effect of vandetanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• vardenafil

  saquinavir increases levels of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. .

• vemurafenib

  vemurafenib and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. Concomitant use of vemurafenib with drugs that prolong QT interval is not recommended. Saquinavir may also increase levels of vemurafenib.

• venlafaxine

  saquinavir, venlafaxine. Either increases toxicity of the other by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. May increase risk for QT prolongation.

• verapamil

  saquinavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• vilanterol/fluticasone furoate inhaled

  saquinavir increases toxicity of vilanterol/fluticasone furoate inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

• vilazodone

  saquinavir increases levels of vilazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If intolerable adverse effects occur when coadministered with moderate CYP3A4 inhibitors, reduce daily dose to 20 mg.

• vincristine

  saquinavir will increase the level or effect of vincristine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• vincristine liposomal

  saquinavir will increase the level or effect of vincristine liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• vorapaxar

  saquinavir increases levels of vorapaxar by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• voriconazole

  voriconazole will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  saquinavir will increase the level or effect of voriconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• vorinostat

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

• voxelotor

  voxelotor will increase the level or effect of saquinavir 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.

Monitor Closely (337)

• abacavir

  saquinavir and abacavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• abemaciclib

  saquinavir will increase the level or effect of abemaciclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong CYP3A4 inhibitors increase plasma levels of abemaciclib and its metabolites. Abemaciclib dose reduction required. If a strong CYP3A4 inhibitor is discontinued, increase abemaciclib to the dose prior to initiating the strong inhibitor.

• acarbose

  saquinavir decreases effects of acarbose by pharmacodynamic antagonism. Use Caution/Monitor. New onset or exacerbation of diabetes mellitus and hyperglycemia have been reported with protease inhibitors.

• albiglutide

  saquinavir decreases effects of albiglutide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• albuterol

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

• alfentanil

  saquinavir increases levels of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• alfuzosin

  saquinavir and alfuzosin both increase QTc interval. Use Caution/Monitor.

• alosetron

  saquinavir increases levels of alosetron by decreasing metabolism. Use Caution/Monitor.

• amlodipine

  saquinavir increases levels of amlodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• amobarbital

  amobarbital will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• apalutamide

  saquinavir will increase the level or effect of apalutamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of apalutamide with strong CYP3A4 or CYP2C8 inhibitors does not require initial dosage modification; however, dose reduction may be needed based on tolerability.

• aprepitant

  aprepitant will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• arformoterol

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

• aripiprazole

  saquinavir increases levels of aripiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. Consider aripiprazole dose reduction by 50%.

• armodafinil

  armodafinil will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• artemether/lumefantrine

  artemether/lumefantrine will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• atazanavir

  atazanavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  atazanavir and saquinavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• atogepant

  saquinavir will increase the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Recommended atogepant dosage is 10 mg PO qDay when coadministered with strong CYP3A4 inhibitors.

• atorvastatin

  atorvastatin will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• bedaquiline

  saquinavir and bedaquiline both increase QTc interval. Modify Therapy/Monitor Closely. ECG should be monitored closely

• benzhydrocodone/acetaminophen

  saquinavir will increase the level or effect of benzhydrocodone/acetaminophen by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with strong CYP3A4 inhibitors may increase hydrocodone (benzhydrocodone is prodrug of hydrocodone) plasma concentrations and can result in potentially fatal respiratory depression.

• berotralstat

  berotralstat will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor or titrate P-gp substrate dose if coadministered.

• betaxolol

  saquinavir, betaxolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• betrixaban

  saquinavir increases levels of betrixaban by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Decrease betrixaban dose to 80 mg PO once, then 40 mg PO qDay if coadministered with a P-gp inhibitor.

• bexarotene

  saquinavir increases levels of bexarotene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. Use alternatives if available. .

• bisoprolol

  saquinavir, bisoprolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• bortezomib

  saquinavir increases levels of bortezomib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• bosentan

  saquinavir will increase the level or effect of bosentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

• bosutinib

  bosutinib increases levels of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• brentuximab vedotin

  saquinavir increases levels of brentuximab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor patients for adverse reactions. .

• brexpiprazole

  saquinavir will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP3A4 inhibitors. If also administered with a strong/moderate CYP2D6 inhibitor, administer a quarter of brexpiprazole dose.

• bromocriptine

  saquinavir increases levels of bromocriptine by decreasing metabolism. Use Caution/Monitor. Increased levels possibly due to CYP3A4 inhibition.

• budesonide

  budesonide will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• buprenorphine

  saquinavir increases levels of buprenorphine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. .

• buprenorphine buccal

  saquinavir increases levels of buprenorphine buccal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. .

• buprenorphine subdermal implant

  saquinavir will increase the level or effect of buprenorphine subdermal implant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor patients already on buprenorphine subdermal implant who require newly-initiated treatment with CYP3A4 inhibitors for signs and symptoms of overmedication. If the dose of the concomitant CYP3A4 inhibitor cannot be reduced or discontinued, implant removal may be necessary and the patient should then be treated with a buprenorphine dosage form that permits dose adjustments. If a CYP3A4 inhibitor is discontinued in a patient who has been stabilized on buprenorphine, monitor the patient for withdrawal.

• buprenorphine, long-acting injection

  saquinavir will increase the level or effect of buprenorphine, long-acting injection by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Patients who transfer to buprenorphine long-acting injection from transmucosal buprenorphine coadministered with CYP3A4 inhibitors should be monitored to ensure buprenorphine plasma levels are adequate. Within 2 weeks, if signs and symptoms of buprenorphine toxicity or overdose occur and the concomitant CYP3A4 inhibitor cannot be reduced or discontinued, transition the patient back to a buprenorphine formulation that permits dose adjustments.

• buspirone

  saquinavir will increase the level or effect of buspirone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• butabarbital

  butabarbital will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• butalbital

  butalbital will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cabazitaxel

  saquinavir increases levels of cabazitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. Avoid coadministration.

• cabozantinib

  saquinavir will increase the level or effect of cabozantinib by Other (see comment). Use Caution/Monitor. MRP2 inhibitors increase cabozantinib toxicity

• calcifediol

  saquinavir, calcifediol. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. CYP450 inhibitors may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1). This may alter serum levels of calcifediol and decrease the conversion of calcifediol to calcitriol. Dose adjustment of calcifediol may be required, and serum 25­hydroxyvitamin D, intact PTH, and serum calcium concentrations should be closely monitored when initiating or discontinuing a strong CYP3A4 inhibitor.

• cannabidiol

  saquinavir will increase the level or effect of cannabidiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Consider reducing the cannabidiol dose when coadministered with a strong CYP3A4 inhibitor.

• capmatinib

  saquinavir will increase the level or effect of capmatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• carbamazepine

  saquinavir will increase the level or effect of carbamazepine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor plasma levels when used concomitantly

• cariprazine

  saquinavir will increase the level or effect of cariprazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with strong CYP3A4 inhibitors requires cariprazine dose reduction. See Dosage Modification section in drug monograph.

• carvedilol

  saquinavir, carvedilol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• cenobamate

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

• ceritinib

  saquinavir increases levels of ceritinib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• chloramphenicol

  chloramphenicol will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• chlordiazepoxide

  saquinavir increases levels of chlordiazepoxide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Use alternatives if available. Consider lowering benzodiazepine dose.

• chloroquine

  saquinavir, chloroquine. Either increases toxicity of the other by QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of QT prolongation and cardiac arrhythmias.

• chlorpromazine

  saquinavir, chlorpromazine. Either increases toxicity of the other by QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR or QT prolongation and cardiac arrhythmias.

• cholic acid

  saquinavir increases toxicity of cholic acid by decreasing elimination. Modify Therapy/Monitor Closely. Avoid concomitant use of inhibitors of the bile salt efflux pump (BSEP). May exacerbate accumulation of conjugated bile salts in the liver and result in clinical symptoms. If concomitant use is necessary, monitor serum transaminases and bilirubin.

• ciprofloxacin

  ciprofloxacin and saquinavir both increase QTc interval. Use Caution/Monitor. Ciprofloxacin elicits minimal effects on QT interval. Caution if used in combination with other drugs known to affect QT interval or in patients with other risk factors.

• citalopram

  saquinavir and citalopram both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended, along with drugs that may prolong the QT interval.

• clarithromycin

  clarithromycin will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• clonazepam

  saquinavir increases levels of clonazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Use alternatives if available. Consider lowering benzodiazepine dose.

• clorazepate

  saquinavir increases levels of clorazepate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Use alternatives if available. Consider lowering benzodiazepine dose.

• clotrimazole

  clotrimazole will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• conivaptan

  conivaptan will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• conjugated estrogens

  saquinavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cortisone

  cortisone will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• crizotinib

  saquinavir increases levels of crizotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Concomitant use of strong CYP3A inhibitors should be avoided. ECG monitoring is recommended, along with drugs that may prolong the QT interval.
  
  crizotinib increases levels of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. ECG monitoring is recommended, along with drugs that may prolong the QT interval.

• crofelemer

  crofelemer increases levels of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 and transporters MRP2 and OATP1A2 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.

• cyclophosphamide

  saquinavir will increase the level or effect of cyclophosphamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cyclosporine

  saquinavir increases levels of cyclosporine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• dabigatran

  saquinavir will increase the level or effect of dabigatran by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Atrial fibrillation: Avoid coadministering dabigatran with P-gp inhibitors if CrCl <30 mL/min. DVT/PE treatment: Avoid coadministering dabigatran with P-gp inhibitors if CrCl <50 mL/min

• darifenacin

  darifenacin will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• darolutamide

  saquinavir will increase the level or effect of darolutamide by Other (see comment). Modify Therapy/Monitor Closely. Darolutamide is a P-gp and CYP3A4 substrate. Closely monitor for increased adverse reactions and modify dose of darolutamide as needed when coadministered with drugs that are both P-gp and strong or moderate CYP3A4 inhibitors.

• darunavir

  darunavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darunavir and saquinavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• dasatinib

  dasatinib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• deferasirox

  deferasirox will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• deflazacort

  saquinavir will increase the level or effect of deflazacort by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Decrease deflazacort dose to one-third of the recommended dose if coadministered with moderate or strong CYP3A4 inhibitors.

• deutetrabenazine

  deutetrabenazine and saquinavir 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).

• dexamethasone

  dexamethasone will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• dexlansoprazole

  dexlansoprazole increases levels of saquinavir by unknown mechanism. Use Caution/Monitor. Potential for increased toxicity. .

• DHEA, herbal

  DHEA, herbal will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• diazepam

  saquinavir increases levels of diazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Use alternatives if available.

• diazepam intranasal

  saquinavir will increase the level or effect of diazepam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong or moderate CYP3A4 inhibitors may decrease rate of diazepam elimination, thereby increasing adverse reactions to diazepam.

• diazoxide

  saquinavir increases effects of diazoxide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• dienogest/estradiol valerate

  saquinavir will increase the level or effect of dienogest/estradiol valerate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Significant changes (increase or decrease) in plasma levels of estrogen and progestin have been seen when HIV protease inhibitors are administered. Monitor for potential adverse effects such as nausea, irregular uterine bleeding, breast tenderness and headache.

• digoxin

  saquinavir increases levels of digoxin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Potential for increased toxicity. .

• diltiazem

  diltiazem will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of diltiazem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• docetaxel

  saquinavir increases levels of docetaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• dolasetron

  saquinavir increases levels of dolasetron by QTc interval. Modify Therapy/Monitor Closely. Potential for increased toxicity. Increased risk of cardiac arrhythmias.

• doravirine

  saquinavir will increase the level or effect of doravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of doravirine and CYP3A4 inhibitors may increase plasma concentrations and toxicities of doravirine.

• doxepin

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

• doxepin cream

  saquinavir will increase the level or effect of doxepin cream by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• dronabinol

  saquinavir will increase the level or effect of dronabinol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dronabinol is a CYP3A4 substrate.

• dronedarone

  dronedarone will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• duvelisib

  saquinavir will increase the level or effect of duvelisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with a strong CYP3A4 inhibitor increases duvelisib AUC, which may increase the risk of duvelisib toxicities. Reduce duvelisib dose to 15 mg BID when coadministered with a strong CYP3A4 inhibitor.
  
  duvelisib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with duvelisib increases AUC of a sensitive CYP3A4 substrate which may increase the risk of toxicities of these drugs. Consider reducing the dose of the sensitive CYP3A4 substrate and monitor for signs of toxicities of the coadministered sensitive CYP3A substrate.

• efavirenz

  efavirenz will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir and efavirenz both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• elagolix

  elagolix will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of elagolix by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration of elagolix 200 mg BID with strong CYP3A inhibitors for >1 month is not recommended. Limit elagolix dose to 150 mg qDay and CYP3A inhibitor duration of use to 6 months if coadministered.
  
  elagolix decreases levels of saquinavir 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

  eliglustat increases levels of saquinavir by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the P-gp substrate and titrate to clinical effect.

• eluxadoline

  eluxadoline increases levels of saquinavir by decreasing metabolism. Use Caution/Monitor. Eluxadoline may increase the systemic exposure of coadministered OATP1B1 substrates.

• elvitegravir

  saquinavir increases levels of elvitegravir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Elvitegravir is a CYP3A4 substrate; if coadministered with strong CYP3A4 inhibitors may increase levels.

• emtricitabine

  saquinavir and emtricitabine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• encorafenib

  encorafenib, saquinavir. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.

• enfortumab vedotin

  saquinavir increases toxicity of enfortumab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Enfortumab vedotin is an antibody-drug conjugate that releases monomethylauristatin E (MMAE) via proteolytic cleavage. MMAE is primarily metabolized by CYP3A4 in vitro. Coadministration with strong CYP3A4 inhibitors may increase free MMAE exposure, which may increase the incidence or severity of toxicities.

• enfuvirtide

  saquinavir and enfuvirtide both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• erythromycin base

  erythromycin base will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• erythromycin ethylsuccinate

  erythromycin ethylsuccinate will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• erythromycin lactobionate

  erythromycin lactobionate will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• erythromycin stearate

  erythromycin stearate will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• eslicarbazepine acetate

  eslicarbazepine acetate will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• esmolol

  saquinavir, esmolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• estradiol vaginal

  saquinavir will increase the level or effect of estradiol vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration with CYP3A4 inhibitors may increase plasma concentrations of estrogens and toxicities.

• eszopiclone

  saquinavir increases levels of eszopiclone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce eszopiclone starting dose to 1 mg/day.

• ethosuximide

  saquinavir increases levels of ethosuximide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• etravirine

  etravirine will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of etravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• exenatide injectable solution

  saquinavir decreases effects of exenatide injectable solution by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• exenatide injectable suspension

  saquinavir decreases effects of exenatide injectable suspension by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors.

• ezogabine

  ezogabine, saquinavir. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Slight and transient QT-prolongation observed with ezogabine, particularly when dose titrated to 1200 mg/day. QT interval should be monitored when ezogabine is prescribed with agents known to increase QT interval.

• famotidine

  famotidine will increase the level or effect of saquinavir by unspecified interaction mechanism. Use Caution/Monitor.

• fedratinib

  fedratinib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• felodipine

  felodipine will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  saquinavir increases levels of felodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• flecainide

  saquinavir increases levels of flecainide by QTc interval. Modify Therapy/Monitor Closely. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• fluconazole

  fluconazole will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fludrocortisone

  fludrocortisone will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• flunisolide inhaled

  saquinavir will increase the level or effect of flunisolide inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fluoxetine

  saquinavir and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.

• flurazepam

  saquinavir increases levels of flurazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Use alternatives if available. Consider lowering benzodiazepine dose.

• fluticasone furoate

  saquinavir will increase the level or effect of fluticasone furoate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inhibitors may increase fluticasone systemic exposure

• fluticasone inhaled

  saquinavir will increase the level or effect of fluticasone inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inhibitors may increase fluticasone systemic exposure

• fluvastatin

  saquinavir increases toxicity of fluvastatin by Other (see comment). Use Caution/Monitor. Comment: OATP1B1 inhibitors may increase risk of myopathy.

• fluvoxamine

  fluvoxamine will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fosamprenavir

  fosamprenavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  fosamprenavir and saquinavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fosphenytoin

  fosphenytoin will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  fosphenytoin will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• fostamatinib

  saquinavir will increase the level or effect of fostamatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong CYP3A4 inhibitors may increase exposure to R406 (fostamatinib major active metabolite). Monitor for toxicities that may require fostamatinib dose reduction.

• fostemsavir

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

• garlic

  garlic decreases levels of saquinavir by unknown mechanism. Use Caution/Monitor.

• gefitinib

  saquinavir increases levels of gefitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration of strong CYP3A4 inhibitors may increase risk for gefitinib adverse effects.

• gemtuzumab

  saquinavir and gemtuzumab both increase QTc interval. Use Caution/Monitor.

• glecaprevir/pibrentasvir

  saquinavir will increase the level or effect of glecaprevir/pibrentasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of glecaprevir/pibrentasvir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  glecaprevir/pibrentasvir will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• glimepiride

  saquinavir decreases effects of glimepiride by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• glipizide

  saquinavir decreases effects of glipizide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• glyburide

  saquinavir decreases effects of glyburide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• goserelin

  goserelin increases toxicity of saquinavir by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• grapefruit

  grapefruit will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• griseofulvin

  griseofulvin will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• guanfacine

  saquinavir will increase the level or effect of guanfacine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong or moderate CYP3A4 inhibitors significantly increase guanfacine plasma concentrations. FDA-approved labeling for extended-release (ER) guanfacine recommends that, if coadministered, the guanfacine dosage should be decreased to half of the recommended dose. Specific recommendations for immediate-release (IR) guanfacine are not available.

• histrelin

  histrelin increases toxicity of saquinavir by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• hydrocodone

  saquinavir will increase the level or effect of hydrocodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with CYP3A4 inhibitors may increase hydrocodone plasma concentrations and can result in potentially fatal respiratory depression

• hydrocortisone

  hydrocortisone will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ibuprofen/famotidine

  ibuprofen/famotidine will increase the level or effect of saquinavir by unspecified interaction mechanism. Use Caution/Monitor.

• ibutilide

  saquinavir increases toxicity of ibutilide by QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of QT prolongation and cardiac arrhythmias.

• ifosfamide

  saquinavir will decrease the level or effect of ifosfamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of CYP3A4 inhibitors may decrease the metabolism of ifosfamide to its active alkylating metabolites and decrease the efficacy of ifosfamide.

• iloperidone

  saquinavir increases levels of iloperidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.
  
  iloperidone increases levels of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.

• imatinib

  saquinavir will increase the level or effect of imatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• indacaterol, inhaled

  saquinavir increases levels of indacaterol, inhaled by Other (see comment). Use Caution/Monitor. Comment: Data suggests that systemic clearance is influenced by modulation of both P-gp and CYP3A4 activities. No dose adjustment is warranted at the 75 mcg dose.
  
  indacaterol, inhaled, saquinavir. QTc interval. Use Caution/Monitor. Drugs that are known to prolong the QTc interval may have an increased the risk of ventricular arrhythmias.

• indinavir

  indinavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  indinavir will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  indinavir and saquinavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• insulin aspart

  saquinavir decreases effects of insulin aspart by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• insulin degludec

  saquinavir decreases effects of insulin degludec by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. HIV protease inhibitors may cause new onset diabetes mellitus (DM), exacerbate existing DM, and cause hyperglycemia due to insulin resistance.

• insulin degludec/insulin aspart

  saquinavir decreases effects of insulin degludec/insulin aspart by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. HIV protease inhibitors may cause new onset diabetes mellitus (DM), exacerbate existing DM, and cause hyperglycemia due to insulin resistance.

• insulin detemir

  saquinavir decreases effects of insulin detemir by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• insulin glargine

  saquinavir decreases effects of insulin glargine by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• insulin glulisine

  saquinavir decreases effects of insulin glulisine by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• insulin inhaled

  saquinavir decreases effects of insulin inhaled by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. HIV protease inhibitors may cause new onset diabetes mellitus (DM), exacerbate existing DM, and cause hyperglycemia due to insulin resistance.

• insulin lispro

  saquinavir decreases effects of insulin lispro by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• insulin NPH

  saquinavir decreases effects of insulin NPH by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• insulin regular human

  saquinavir decreases effects of insulin regular human by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• isoniazid

  isoniazid will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• isradipine

  saquinavir increases levels of isradipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• istradefylline

  saquinavir will increase the level or effect of istradefylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Do not exceed istradefylline 20 mg/day if coadministered with strong CYP3A4 inhibitors.
  
  istradefylline will increase the level or effect of saquinavir 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.
  
  istradefylline will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of P-gp substrates in clinical trials. Consider dose reduction of sensitive P-gp substrates.

• itraconazole

  itraconazole will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Limit itraconazole dose to 200 mg/day in patients receiving saquinavir/ritonavir.
  
  itraconazole will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Limit itraconazole dose to 200 mg/day in patients receiving saquinavir/ritonavir.

• ivacaftor

  saquinavir will increase the level or effect of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce ivacaftor dose if coadministered with strong CYP3A4 inhibitors. See specific ivacaftor-containing product for precise dosage modification.
  
  ivacaftor increases levels of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Ivacaftor and its M1 metabolite has the potential to inhibit P-gp; may significantly increase systemic exposure to sensitive P-gp substrates with a narrow therapeutic index.

• ketamine

  saquinavir will decrease the level or effect of ketamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ketoconazole

  ketoconazole will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• labetalol

  saquinavir, labetalol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR or QT prolongation and cardiac arrhythmias.

• lacosamide

  saquinavir increases levels of lacosamide by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Potential for increased toxicity. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.
  
  saquinavir increases levels of lacosamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Consider decreasing lacosamide dose when coadministered with strong CYP3A4 inhibitors.

• lamivudine

  saquinavir and lamivudine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• lansoprazole

  lansoprazole increases levels of saquinavir by unknown mechanism. Use Caution/Monitor. Potential for increased toxicity. .

• lapatinib

  lapatinib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  lapatinib will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• lenvatinib

  saquinavir and lenvatinib both increase QTc interval. Use Caution/Monitor. Lenvatinib prescribing information recommends monitoring ECG closely when coadministered with QT prolonging drugs.

• letermovir

  saquinavir increases levels of letermovir by decreasing metabolism. Use Caution/Monitor. Coadminstration of letermovir, an OATP1B1/3 substrate, with OATP1B1/3 inhibitors may increase letermovir plasma concentrations.
  
  letermovir increases levels of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• leuprolide

  leuprolide increases toxicity of saquinavir by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• levalbuterol

  levalbuterol, saquinavir. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Increased risk of hypokalemia, QT prolongation, and cardiac arrhythmias.

• levamlodipine

  saquinavir will increase the level or effect of levamlodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with moderate and strong CYP3A inhibitors results in increased systemic exposure to amlodipine and may require dose reduction. Monitor for symptoms of hypotension and edema when amlodipine is coadministered with CYP3A inhibitors to determine the need for dose adjustment.

• levobunolol

  saquinavir, levobunolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• levoketoconazole

  levoketoconazole will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• levomilnacipran

  saquinavir will increase the level or effect of levomilnacipran by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Do not exceed 80 mg/day of levomilnacipran when coadministered with strong CYP3A4 inhibitors

• linagliptin

  saquinavir decreases effects of linagliptin by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .
  
  saquinavir will increase the level or effect of linagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• liraglutide

  saquinavir decreases effects of liraglutide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• lomitapide

  lomitapide increases levels of saquinavir by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Consider reducing dose when used concomitantly with lomitapide.

• lopinavir

  lopinavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• loratadine

  loratadine will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• lumacaftor/ivacaftor

  saquinavir increases levels of lumacaftor/ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong CYP3A inhibitors do not impact lumacaftor exposure, but increased ivacaftor exposure by 4.3-fold. Due to the induction effect of lumacaftor on CYP3A, at steady-state the net exposure of ivacaftor is not expected to exceed that when given in the absence of lumacaftor at a dose of 150 mg q12hr (the approved dose of ivacaftor monotherapy). Therefore, no dose adjustment is necessary when CYP3A inhibitors are initiated in patients currently taking lumacaftor/ivacaftor. However, when initiating lumacaftor/ivacaftor in patients taking strong CYP3A inhibitors, reduce the dose to 1 tablet daily (lumacaftor 200 mg/ivacaftor 125 mg total daily dose) for the first week of treatment to allow for the steady-state induction effect of lumacaftor. Following this period, continue with the recommended daily dose. No dose adjustment is required for moderate or weak CYP3A4 inhibitors.

• lumateperone

  saquinavir will increase the level or effect of lumateperone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce lumateperone dose to 10.5 mg/day if coadministered with strong CYP3A4 inhibitors.

• lumefantrine

  lumefantrine will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• maraviroc

  saquinavir increases levels of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. Adjust maraviroc dose to 150mg BID.

• marijuana

  marijuana will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of marijuana by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• mavacamten

  saquinavir will increase the level or effect of mavacamten by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Inititiation of weak CYP2C19 inhibitors may require decreased mavacamten dose.

• metformin

  saquinavir decreases effects of metformin by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• methylprednisolone

  methylprednisolone will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of methylprednisolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• metoprolol

  saquinavir, metoprolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• metronidazole

  metronidazole will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• miconazole vaginal

  miconazole vaginal will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• mifepristone

  saquinavir will increase the level or effect of mifepristone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Do not exceed mifepristone 300 mg/day for Cushing syndrome when coadministered with strong CYP3A4 inhibitors; combination may also prolong QT interval. Use alternatives if available

• miglitol

  saquinavir decreases effects of miglitol by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• mipomersen

  mipomersen, saquinavir. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Both drugs have potential to increase hepatic enzymes; monitor LFTs.

• mirtazapine

  saquinavir will increase the level or effect of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  mirtazapine and saquinavir both increase QTc interval. Use Caution/Monitor.

• mitotane

  mitotane decreases levels of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.

• modafinil

  saquinavir will increase the level or effect of modafinil by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available.
  
  saquinavir will increase the level or effect of modafinil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• mometasone inhaled

  saquinavir will increase the level or effect of mometasone inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increases riak for systemic corticosteroid side effects

• mometasone, intranasal

  saquinavir will increase the level or effect of mometasone, intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• nadolol

  saquinavir, nadolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• nafcillin

  nafcillin will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• naldemedine

  saquinavir increases levels of naldemedine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor naldemedine for potential adverse effects if coadministered with strong or moderate CYP3A4 inhibitors.
  
  saquinavir increases levels of naldemedine by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor naldemedine for potential adverse effects if coadministered with P-gp inhibitors.

• nateglinide

  saquinavir decreases effects of nateglinide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• nebivolol

  saquinavir, nebivolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• nefazodone

  nefazodone will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nefazodone will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• nelfinavir

  nelfinavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nelfinavir and saquinavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• netupitant/palonosetron

  saquinavir will increase the level or effect of netupitant/palonosetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Netupitant is mainly metabolized by CYP3A4; no dosage adjustment is required

• nevirapine

  nevirapine will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir and nevirapine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• nicardipine

  nicardipine will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  saquinavir increases levels of nicardipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• nifedipine

  nifedipine will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nifedipine will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  saquinavir increases levels of nifedipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. Consider initiating nifedipine at the lowest dose available if given concomitantly with this medication.

• nilotinib

  nilotinib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nilotinib will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• nimodipine

  saquinavir increases levels of nimodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• nintedanib

  saquinavir increases levels of nintedanib by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. If nintedanib adverse effects occur, management may require interruption, dose reduction, or discontinuation of therapy .

• nirmatrelvir

  nirmatrelvir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Patients on ritonavir- or cobicistat-containing HIV regimens should continue their treatment as indicated. Monitor for increased nirmatrelvir/ritonavir or protease inhibitor adverse events with concomitant use.

• nirmatrelvir/ritonavir

  nirmatrelvir/ritonavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Patients on ritonavir- or cobicistat-containing HIV regimens should continue their treatment as indicated. Monitor for increased nirmatrelvir/ritonavir or protease inhibitor adverse events with concomitant use.

• nisoldipine

  saquinavir increases levels of nisoldipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• nizatidine

  nizatidine will increase the level or effect of saquinavir by unspecified interaction mechanism. Use Caution/Monitor.

• ofloxacin

  saquinavir increases levels of ofloxacin by QTc interval. Modify Therapy/Monitor Closely. Potential for increased toxicity. Use alternatives if available. Increased risk of QT prolongation and cardiac arrhythmias.

• oliceridine

  saquinavir will increase the level or effect of oliceridine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If concomitant use is necessary, may require less frequent oliceridine dosing. Closely monitor for respiratory depression and sedation and titrate subsequent doses accordingly. If inhibitor is discontinued, consider increase oliceridine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal.

• olodaterol inhaled

  saquinavir and olodaterol inhaled both increase QTc interval. Use Caution/Monitor. Drugs that prolong the QTc interval and may potentiate the effects of beta2 agonists on the cardiovascular system; increased risk of ventricular arrhythmias

• orlistat

  orlistat will decrease the level or effect of saquinavir by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Loss of virological control reported in HIV-infected patients taking orlistat concomitantly. Exact mechanism is unclear, but may include a drug-drug interaction that inhibits systemic absorption of the antiretroviral drug. Monitor HIV RNA levels frequently and if increased HIV viral load confirmed, discontinue orlistat.

• osilodrostat

  saquinavir will increase the level or effect of osilodrostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce dose of osilodrostat, a CYP3A4 substrate, by half when coadministered with a strong CYP3A4 inhibitor.
  
  osilodrostat and saquinavir both increase QTc interval. Use Caution/Monitor.

• osimertinib

  osimertinib and saquinavir both increase QTc interval. Use Caution/Monitor. Conduct periodic monitoring with ECGs and electrolytes in patients taking drugs known to prolong the QTc interval.

• ospemifene

  saquinavir increases levels of ospemifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• oxaliplatin

  oxaliplatin will increase the level or effect of saquinavir by Other (see comment). Use Caution/Monitor. Monitor for ECG changes if therapy is initiated in patients with drugs known to prolong QT interval.

• oxcarbazepine

  oxcarbazepine will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ozanimod

  ozanimod and saquinavir both increase QTc interval. Modify Therapy/Monitor Closely. The potential additive effects on heart rate, treatment with ozanimod should generally not be initiated in patients who are concurrently treated with QT prolonging drugs with known arrhythmogenic properties.

• paclitaxel

  saquinavir will increase the level or effect of paclitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• paclitaxel protein bound

  saquinavir will increase the level or effect of paclitaxel protein bound by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• panobinostat

  saquinavir increases levels of panobinostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce panobinostat starting dose to 10 mg if coadministered with strong CYP3A4 inhibitors.

• pantoprazole

  pantoprazole will decrease the level or effect of saquinavir by unknown mechanism. Use Caution/Monitor. Potential for increased toxicity.

• paricalcitol

  saquinavir increases levels of paricalcitol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• pasireotide

  saquinavir and pasireotide both increase QTc interval. Modify Therapy/Monitor Closely.

• penbutolol

  saquinavir, penbutolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• pentobarbital

  pentobarbital will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• perampanel

  saquinavir will increase the level or effect of perampanel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• phenobarbital

  phenobarbital will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  phenobarbital will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• phenytoin

  phenytoin will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Clinicians may want to consider using alternative medication to phenytoin in patients on saquinavir therapy. However, if it becomes necessary to give these agents concurrently, upward adjustments in saquinavir dosing may be needed to maintain antiviral effectiveness.
  
  phenytoin will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• pindolol

  saquinavir, pindolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• pitavastatin

  saquinavir increases toxicity of pitavastatin by Other (see comment). Use Caution/Monitor. Comment: OATP1B1 inhibitors may increase risk of myopathy.

• polatuzumab vedotin

  saquinavir will increase the level or effect of polatuzumab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Polatuzumab undergoes catabolism to small peptides, amino acids, monomethyl auristatin E (MMAE), and unconjugated MMAE-related catabolites. MMAE is a CYP3A4 substrate. Coadministration of polatuzumab vedotin with a strong CYP3A4 inhibitor may increase unconjugated MMAE AUC, which may increase polatuzumab vedotin toxicities.

• ponatinib

  ponatinib increases levels of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• posaconazole

  posaconazole will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• pramlintide

  saquinavir decreases effects of pramlintide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• pravastatin

  saquinavir increases toxicity of pravastatin by Other (see comment). Use Caution/Monitor. Comment: OATP1B1 inhibitors may increase risk of myopathy.

• praziquantel

  saquinavir will increase the level or effect of praziquantel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• prednisone

  prednisone will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• primidone

  primidone will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• progesterone intravaginal gel

  saquinavir will increase the level or effect of progesterone intravaginal gel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• progesterone micronized

  saquinavir will increase the level or effect of progesterone micronized by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• progesterone, natural

  saquinavir will increase the level or effect of progesterone, natural by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• quercetin

  quercetin will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• quetiapine

  saquinavir increases levels of quetiapine by QTc interval. Modify Therapy/Monitor Closely. Potential for increased toxicity. Use alternatives if available. Increased risk of QT prolongation and cardiac arrhythmias.
  
  quetiapine, saquinavir. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.

• quinine

  saquinavir and quinine both increase QTc interval. Use Caution/Monitor.

• quinupristin/dalfopristin

  quinupristin/dalfopristin will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• rabeprazole

  rabeprazole will increase the level or effect of saquinavir by unknown mechanism. Use Caution/Monitor. Potential for increased toxicity.

• ranolazine

  ranolazine will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• repaglinide

  saquinavir will increase the level or effect of repaglinide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• rifabutin

  rifabutin decreases levels of saquinavir by increasing metabolism. Use Caution/Monitor. If saquinavir administered with ritonavir as boosted therapy, interaction not clinically significant.

• rifapentine

  rifapentine will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• rifaximin

  saquinavir increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• rilpivirine

  saquinavir increases levels of rilpivirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Rilpivirine is not expected to affect the plasma concentrations of co-administered protease inhibitors. .
  
  rilpivirine increases toxicity of saquinavir by QTc interval. Use Caution/Monitor. Rilpivirine should be used with caution when co-administered with a drug with a known risk of Torsade de Pointes.

• ripretinib

  saquinavir will increase the level or effect of ripretinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration with a strong CYP3A inhibitor will increase systemic exposure to ripretinib and its active metabolite (DP-5439), which may increase risk of adverse reactions.

• ritonavir

  ritonavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Saquinavir is intended to be administered with ritonavir (boosted therapy). The combination has shown to cause dose-dependent QT and PR interval prolongation. Caution in treatment naïve patients. Reduce starting dose and perform an on-treatment ECG after approximately 10 days.
  
  ritonavir will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  ritonavir and saquinavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• rivaroxaban

  saquinavir increases levels of rivaroxaban by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Avoid concomitant use of rivaroxaban and combined Pgp and strong CYP3A4 inhibitors. Combination may lead to significant increases in rivaroxaban levels and increase bleeding risk.

• rosiglitazone

  saquinavir decreases effects of rosiglitazone by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• rucaparib

  rucaparib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.

• rufinamide

  rufinamide will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• sacubitril/valsartan

  saquinavir will increase the level or effect of sacubitril/valsartan by Other (see comment). Use Caution/Monitor. The results from an in vitro study with human liver tissue indicate that valsartan is a substrate of the hepatic uptake transporter OATP1B1; coadministration with OATP1B1 inhibitors may increase valsartan systemic exposure

• salmeterol

  saquinavir increases levels of salmeterol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• sarecycline

  sarecycline will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor for toxicities of P-gp substrates that may require dosage reduction when coadministered with P-gp inhibitors.

• saxagliptin

  saquinavir will increase the level or effect of saxagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Limit saxagliptin dose to 2.5 mg/day when coadministered with strong CYP3A4 inhibitors

• secobarbital

  secobarbital will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• selpercatinib

  selpercatinib increases toxicity of saquinavir by QTc interval. Use Caution/Monitor.

• sildenafil

  saquinavir increases levels of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. Increased risk of priapism, hypotension, and other adverse effects.

• silodosin

  saquinavir increases levels of silodosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. Use alternatives if available.

• sirolimus

  sirolimus will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• sitagliptin

  saquinavir decreases effects of sitagliptin by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• sofosbuvir/velpatasvir

  saquinavir will increase the level or effect of sofosbuvir/velpatasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• sorafenib

  sorafenib and saquinavir both increase QTc interval. Use Caution/Monitor.

• St John's Wort

  St John's Wort will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• stavudine

  saquinavir and stavudine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• stiripentol

  stiripentol, saquinavir. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.
  
  stiripentol will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Consider reducing the dose of P-glycoprotein (P-gp) substrates, if adverse reactions are experienced when administered concomitantly with stiripentol.
  
  saquinavir will increase the level or effect of stiripentol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• sufentanil

  saquinavir will increase the level or effect of sufentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• sufentanil SL

  saquinavir will increase the level or effect of sufentanil SL by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of sufentanil SL with any CYP3A4 inhibitor may increase sufentanil plasma concentration, and, thereby increase or prolonged adverse effects, including potentially fatal respiratory depression.

• tacrolimus

  tacrolimus will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• tacrolimus ointment

  saquinavir will increase the level or effect of tacrolimus ointment by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tadalafil

  saquinavir increases levels of tadalafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• tamoxifen

  saquinavir, tamoxifen. Either increases effects of the other by QTc interval. Use Caution/Monitor.

• tasimelteon

  saquinavir will increase the level or effect of tasimelteon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tazemetostat

  tazemetostat will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tecovirimat

  tecovirimat will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.

• teniposide

  saquinavir will increase the level or effect of teniposide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• tenofovir DF

  saquinavir and tenofovir DF both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• terbinafine

  saquinavir will increase the level or effect of terbinafine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tezacaftor

  saquinavir will increase the level or effect of tezacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust tezacaftor dosage regimen if coadministered with a strong CYP3A inhibitor.

• thioridazine

  saquinavir, thioridazine. Either increases toxicity of the other by QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available.

• ticagrelor

  saquinavir increases levels of ticagrelor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Ticagrelor is metabolized by CYP3A4/5. Avoid use with strong CYP3A inhibitors.

• timolol

  saquinavir, timolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• tinidazole

  saquinavir will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tipranavir

  saquinavir and tipranavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• tisotumab vedotin

  saquinavir increases levels of tisotumab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tisotumab vedotin?s active metabolite (MMAE) is a CYP3A4 substrate. Coadministration with strong CYP3A4 inhibitors may increase unconjugated MMAE systemic exposure and increase risk of adverse effects.

• tolvaptan

  tolvaptan will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• topiramate

  topiramate will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• toremifene

  saquinavir increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

• tramadol

  saquinavir will increase the level or effect of tramadol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• triamcinolone acetonide injectable suspension

  saquinavir will increase the level or effect of triamcinolone acetonide injectable suspension by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• triclabendazole

  triclabendazole and saquinavir both increase QTc interval. Use Caution/Monitor.

• trimipramine

  saquinavir will increase the level or effect of trimipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• triptorelin

  triptorelin increases toxicity of saquinavir by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• tucatinib

  tucatinib will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Consider reducing the dosage of P-gp substrates, where minimal concentration changes may lead to serious or life-threatening toxicities.

• ulipristal

  saquinavir will increase the level or effect of ulipristal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• umeclidinium bromide/vilanterol inhaled

  saquinavir will increase the level or effect of umeclidinium bromide/vilanterol inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Vilanterol is a CYP3A4 substrate; coadministration with potent CYP3A4 inhibitors may increase systemic exposure

• upadacitinib

  saquinavir will increase the level or effect of upadacitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Caution if upadacitinib is coadministered with strong CYP3A4 inhibitors.

• valbenazine

  saquinavir will increase the level or effect of valbenazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce valbenazine dose to 40 mg once daily when coadministered with a strong CYP3A4 inhibitor.

• valsartan

  saquinavir will increase the level or effect of valsartan by Other (see comment). Use Caution/Monitor. The results from an in vitro study with human liver tissue indicate that valsartan is a substrate of the hepatic uptake transporter OATP1B1; coadministration with OATP1B1 inhibitors may increase valsartan systemic exposure

• velpatasvir

  saquinavir will increase the level or effect of velpatasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• verapamil

  verapamil will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• vilanterol/fluticasone furoate inhaled

  saquinavir will increase the level or effect of vilanterol/fluticasone furoate inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Fluticasone furoate and vilanterol are both CYP3A4 substrates; coadministration with potent CYP3A4 inhibitors may increase systemic exposure

• vinblastine

  saquinavir will increase the level or effect of vinblastine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• vinorelbine

  saquinavir will increase the level or effect of vinorelbine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• voclosporin

  voclosporin, saquinavir. Either increases effects of the other by QTc interval. Use Caution/Monitor.

• voxilaprevir

  saquinavir will increase the level or effect of voxilaprevir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• warfarin

  saquinavir will increase the level or effect of warfarin by Other (see comment). Use Caution/Monitor. Warfarin's less potent R-enantiomer is metabolized in part by CYP3A4 (and also CYP1A2 and CYP2C19). Monitor INR more frequently if coadministered with inhibitors of these isoenzymes and adjust warfarin dose if needed.

• zafirlukast

  zafirlukast will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• zanubrutinib

  saquinavir will increase the level or effect of zanubrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce zanubrutinib dose when coadministered with a strong CYP3A4 inhibitor. Interrupt dose as recommended for adverse reactions. After discontinuing the CYP3A4 inhibitor, resume previous dose of zanubrutinib. See zanubrutinib Dosage Modifications for precise recommendation.

• zidovudine

  saquinavir and zidovudine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• zolpidem

  saquinavir will increase the level or effect of zolpidem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• zonisamide

  saquinavir will increase the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

Minor (6)

• cilostazol

  saquinavir increases levels of cilostazol by decreasing metabolism. Minor/Significance Unknown.

• food

  food increases levels of saquinavir by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• ganaxolone

  saquinavir, ganaxolone. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. Changes in ganaxolone exposures when coadministered with strong, moderate, or weak CYP3A4 inhibitors are not expected to be clinically significant.

• ixazomib

  saquinavir, ixazomib. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. In clinical trials, coadministration of ixazomib with strong CYP3A inhibitors did not result in a clinically meaningful change in the systemic exposure of ixazomib.

• paclitaxel

  saquinavir increases levels of paclitaxel by decreasing metabolism. Minor/Significance Unknown.

• paclitaxel protein bound

  saquinavir increases levels of paclitaxel protein bound by decreasing metabolism. Minor/Significance Unknown.

• abacavir

  Monitor Closely (1)saquinavir and abacavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• abametapir

  Serious - Use Alternative (1)abametapir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.

• abemaciclib

  Monitor Closely (1)saquinavir will increase the level or effect of abemaciclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong CYP3A4 inhibitors increase plasma levels of abemaciclib and its metabolites. Abemaciclib dose reduction required. If a strong CYP3A4 inhibitor is discontinued, increase abemaciclib to the dose prior to initiating the strong inhibitor.

• acalabrutinib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of acalabrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of acalabrutinib with strong CYP3A inhibitors. If a strong CYP3A inhibitor must be used short-term (eg, up to 7 days), temporarily interrupt treatment with acalabrutinib.

• acarbose

  Monitor Closely (1)saquinavir decreases effects of acarbose by pharmacodynamic antagonism. Use Caution/Monitor. New onset or exacerbation of diabetes mellitus and hyperglycemia have been reported with protease inhibitors.

• acebutolol

  Serious - Use Alternative (1)saquinavir, acebutolol. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of PR prolongation and cardiac arrhythmias.

• ado-trastuzumab emtansine

  Serious - Use Alternative (1)saquinavir increases levels of ado-trastuzumab emtansine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. DM1, the cytotoxic component, is metabolized mainly by CYP3A4; strong CYP3A4 inhibitors may increase DM1 exposure and toxicity.

• afatinib

  Serious - Use Alternative (1)saquinavir increases levels of afatinib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. Reduce afatinib daily dose by 10 mg if not tolerated when coadministered with P-gp inhibitors.

• albiglutide

  Monitor Closely (1)saquinavir decreases effects of albiglutide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• albuterol

  Contraindicated (1)saquinavir, albuterol. Either increases toxicity of the other by pharmacodynamic synergism. Contraindicated. Contraindicated. Saquinavir boosted with ritonavir increases risk of hypokalemia, QT prolongation, and cardiac arrhythmias.Monitor Closely (1)albuterol and saquinavir both increase QTc interval. Use Caution/Monitor.

• alfentanil

  Monitor Closely (1)saquinavir increases levels of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• alfuzosin

  Contraindicated (2)saquinavir increases levels of alfuzosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Potential for increased toxicity. .
  
  alfuzosin and saquinavir both increase QTc interval. Contraindicated.Monitor Closely (1)saquinavir and alfuzosin both increase QTc interval. Use Caution/Monitor.

• almotriptan

  Serious - Use Alternative (1)saquinavir increases levels of almotriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid use in patients with renal or hepatic impairment.

• alosetron

  Monitor Closely (1)saquinavir increases levels of alosetron by decreasing metabolism. Use Caution/Monitor.

• alprazolam

  Serious - Use Alternative (1)saquinavir increases levels of alprazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Avoid coadministration. If need to use, decrease alprazolam dose.

• amiodarone

  Contraindicated (1)amiodarone will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Contraindicated.Serious - Use Alternative (1)saquinavir will increase the level or effect of amiodarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• amisulpride

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

• amlodipine

  Monitor Closely (1)saquinavir increases levels of amlodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• amobarbital

  Monitor Closely (1)amobarbital will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• anagrelide

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

• apalutamide

  Monitor Closely (1)saquinavir will increase the level or effect of apalutamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of apalutamide with strong CYP3A4 or CYP2C8 inhibitors does not require initial dosage modification; however, dose reduction may be needed based on tolerability.Serious - Use Alternative (1)apalutamide will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.

• apixaban

  Serious - Use Alternative (1)saquinavir will increase the level or effect of apixaban by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If taking apixaban dose >2.5 mg BID, decrease dose by 50% if coadministered with strong dual inhibitors of CYP3A4 and P-gp; if currently taking apixaban 2.5 mg PO BID, avoid coadministration with strong dual inhibitors of CYP3A4 and P-gp

• apomorphine

  Serious - Use Alternative (2)saquinavir, apomorphine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.
  
  apomorphine and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• aprepitant

  Monitor Closely (1)aprepitant will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of aprepitant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• arformoterol

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

• aripiprazole

  Monitor Closely (1)saquinavir increases levels of aripiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. Consider aripiprazole dose reduction by 50%.Serious - Use Alternative (1)aripiprazole and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• armodafinil

  Monitor Closely (1)armodafinil will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• arsenic trioxide

  Serious - Use Alternative (1)saquinavir, arsenic trioxide. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.

• artemether

  Contraindicated (1)artemether and saquinavir both increase QTc interval. Contraindicated.Serious - Use Alternative (1)saquinavir increases levels of artemether by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• artemether/lumefantrine

  Monitor Closely (1)artemether/lumefantrine will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir increases levels of artemether/lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• asenapine

  Serious - Use Alternative (2)saquinavir, asenapine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.
  
  asenapine and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• asenapine transdermal

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

• astemizole

  Contraindicated (1)saquinavir will increase the level or effect of astemizole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• atazanavir

  Contraindicated (1)saquinavir will increase the level or effect of atazanavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Monitor Closely (2)atazanavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  atazanavir and saquinavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• atenolol

  Serious - Use Alternative (1)saquinavir, atenolol. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of PR prolongation and cardiac arrhythmias.

• atogepant

  Monitor Closely (1)saquinavir will increase the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Recommended atogepant dosage is 10 mg PO qDay when coadministered with strong CYP3A4 inhibitors.

• atomoxetine

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

• atorvastatin

  Monitor Closely (1)atorvastatin will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (2)saquinavir increases toxicity of atorvastatin by Other (see comment). Avoid or Use Alternate Drug. Comment: OATP1B1 inhibitors may increase risk of myopathy.
  
  saquinavir will increase the level or effect of atorvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Limit atorvastatin dose to 20 mg/day

• avanafil

  Serious - Use Alternative (1)saquinavir will increase the level or effect of avanafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. CYP3A4 inhibitors may reduce avanafil clearance increasing systemic exposure to avanafil; significantly increased levels may result in significant adverse events including severe hypotension, syncope, visual changes, and priapism. Coadministration with strong CYP3A4 is contraindicated.

• avapritinib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of avapritinib with strong CYP3A4 inhibitors.

• axitinib

  Serious - Use Alternative (1)saquinavir increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, reduce axitinib dose by 50%.

• azithromycin

  Serious - Use Alternative (1)saquinavir, azithromycin. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.

• bedaquiline

  Monitor Closely (1)saquinavir and bedaquiline both increase QTc interval. Modify Therapy/Monitor Closely. ECG should be monitored closelySerious - Use Alternative (1)saquinavir will increase the level or effect of bedaquiline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of bedaquiline with strong CYP3A4 inhibitors for >14 consecutive days, unless the benefit of treatment outweighs the risk

• benzhydrocodone/acetaminophen

  Monitor Closely (1)saquinavir will increase the level or effect of benzhydrocodone/acetaminophen by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with strong CYP3A4 inhibitors may increase hydrocodone (benzhydrocodone is prodrug of hydrocodone) plasma concentrations and can result in potentially fatal respiratory depression.

• berotralstat

  Monitor Closely (1)berotralstat will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor or titrate P-gp substrate dose if coadministered.

• betaxolol

  Monitor Closely (1)saquinavir, betaxolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• betibeglogene autotemcel

  Serious - Use Alternative (1)saquinavir, betibeglogene autotemcel. Other (see comment). Avoid or Use Alternate Drug. Comment: Do not take antiretroviral medications for at least 1 month before mobilization or expected duration for elimination of the medications, and until all cycles of apheresis are completed. Antiretroviral medications may interfere with manufacturing of apheresed cells.

• betrixaban

  Monitor Closely (1)saquinavir increases levels of betrixaban by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Decrease betrixaban dose to 80 mg PO once, then 40 mg PO qDay if coadministered with a P-gp inhibitor.

• bexarotene

  Monitor Closely (1)saquinavir increases levels of bexarotene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. Use alternatives if available. .

• bisoprolol

  Monitor Closely (1)saquinavir, bisoprolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• bortezomib

  Monitor Closely (1)saquinavir increases levels of bortezomib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• bosentan

  Monitor Closely (1)saquinavir will increase the level or effect of bosentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)bosentan will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. stop bosentan >36 hours prior to PI initiation and restart 10 days after PI initiation at 62.5 mg once daily or every other day.

• bosutinib

  Monitor Closely (1)bosutinib increases levels of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (2)saquinavir increases levels of bosutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Strong CYP3A4 inhibitors increases bosutinib plasma concentration ~5-fold.
  
  saquinavir increases levels of bosutinib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• brentuximab vedotin

  Monitor Closely (1)saquinavir increases levels of brentuximab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor patients for adverse reactions. .

• brexpiprazole

  Monitor Closely (1)saquinavir will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP3A4 inhibitors. If also administered with a strong/moderate CYP2D6 inhibitor, administer a quarter of brexpiprazole dose.

• brigatinib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of brigatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If concomitant use of a strong CYP3A inhibitor cannot be avoided, reduce the brigatinib once daily dose by about 50% (ie, from 180 mg to 90 mg, or from 90 mg to 60 mg). After discontinuation of a strong CYP3A inhibitor, resume the brigatinib dose that was tolerated prior to initiating the strong CYP3A inhibitor.

• bromocriptine

  Monitor Closely (1)saquinavir increases levels of bromocriptine by decreasing metabolism. Use Caution/Monitor. Increased levels possibly due to CYP3A4 inhibition.Serious - Use Alternative (1)saquinavir will increase the level or effect of bromocriptine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• budesonide

  Monitor Closely (1)budesonide will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of budesonide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• buprenorphine

  Monitor Closely (1)saquinavir increases levels of buprenorphine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. .Serious - Use Alternative (1)buprenorphine and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• buprenorphine buccal

  Monitor Closely (1)saquinavir increases levels of buprenorphine buccal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. .

• buprenorphine subdermal implant

  Monitor Closely (1)saquinavir will increase the level or effect of buprenorphine subdermal implant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor patients already on buprenorphine subdermal implant who require newly-initiated treatment with CYP3A4 inhibitors for signs and symptoms of overmedication. If the dose of the concomitant CYP3A4 inhibitor cannot be reduced or discontinued, implant removal may be necessary and the patient should then be treated with a buprenorphine dosage form that permits dose adjustments. If a CYP3A4 inhibitor is discontinued in a patient who has been stabilized on buprenorphine, monitor the patient for withdrawal.

• buprenorphine transdermal

  Serious - Use Alternative (1)saquinavir will increase the level or effect of buprenorphine transdermal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• buprenorphine, long-acting injection

  Monitor Closely (1)saquinavir will increase the level or effect of buprenorphine, long-acting injection by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Patients who transfer to buprenorphine long-acting injection from transmucosal buprenorphine coadministered with CYP3A4 inhibitors should be monitored to ensure buprenorphine plasma levels are adequate. Within 2 weeks, if signs and symptoms of buprenorphine toxicity or overdose occur and the concomitant CYP3A4 inhibitor cannot be reduced or discontinued, transition the patient back to a buprenorphine formulation that permits dose adjustments.

• buspirone

  Monitor Closely (1)saquinavir will increase the level or effect of buspirone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• butabarbital

  Monitor Closely (1)butabarbital will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• butalbital

  Monitor Closely (1)butalbital will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cabazitaxel

  Monitor Closely (1)saquinavir increases levels of cabazitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. Avoid coadministration.

• cabergoline

  Serious - Use Alternative (1)saquinavir increases levels of cabergoline by decreasing metabolism. Contraindicated.

• cabotegravir

  Serious - Use Alternative (1)saquinavir, cabotegravir. Other (see comment). Avoid or Use Alternate Drug. Comment: Cabotegravir plus rilpivirine is a complete regimen. Coadministration with other antiretroviral medications for treating HIV-1 infection is not recommended.

• cabozantinib

  Monitor Closely (1)saquinavir will increase the level or effect of cabozantinib by Other (see comment). Use Caution/Monitor. MRP2 inhibitors increase cabozantinib toxicitySerious - Use Alternative (1)saquinavir will increase the level or effect of cabozantinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of cabozantinib with strong CYP3A4 inhibitors. If a strong CYP3A4 inhibitor is required, decrease cabozantinib dose by 40 mg/day (Cometriq) or by 20 mg/day (Cabometyx). Resume previous dose 2-3 days after strong CYP3A4 inhibitor discontinued.

• calcifediol

  Monitor Closely (1)saquinavir, calcifediol. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. CYP450 inhibitors may inhibit enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1). This may alter serum levels of calcifediol and decrease the conversion of calcifediol to calcitriol. Dose adjustment of calcifediol may be required, and serum 25­hydroxyvitamin D, intact PTH, and serum calcium concentrations should be closely monitored when initiating or discontinuing a strong CYP3A4 inhibitor.

• cannabidiol

  Monitor Closely (1)saquinavir will increase the level or effect of cannabidiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Consider reducing the cannabidiol dose when coadministered with a strong CYP3A4 inhibitor.

• capmatinib

  Monitor Closely (1)saquinavir will increase the level or effect of capmatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• carbamazepine

  Monitor Closely (1)saquinavir will increase the level or effect of carbamazepine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor plasma levels when used concomitantlySerious - Use Alternative (1)carbamazepine will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• cariprazine

  Monitor Closely (1)saquinavir will increase the level or effect of cariprazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with strong CYP3A4 inhibitors requires cariprazine dose reduction. See Dosage Modification section in drug monograph.

• carvedilol

  Monitor Closely (1)saquinavir, carvedilol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• cenobamate

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

• ceritinib

  Contraindicated (1)ceritinib and saquinavir both increase QTc interval. Contraindicated.Monitor Closely (1)saquinavir increases levels of ceritinib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir increases levels of ceritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid if possible; if concomitant use is unavoidable, reduce ceritinib dose by ~33%; after discontinuation of strong CYP3A inhibitor, resume at previous dose.

• chloramphenicol

  Monitor Closely (1)chloramphenicol will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• chlordiazepoxide

  Monitor Closely (1)saquinavir increases levels of chlordiazepoxide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Use alternatives if available. Consider lowering benzodiazepine dose.

• chloroquine

  Contraindicated (1)chloroquine increases toxicity of saquinavir by QTc interval. Contraindicated.Monitor Closely (1)saquinavir, chloroquine. Either increases toxicity of the other by QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of QT prolongation and cardiac arrhythmias.Serious - Use Alternative (1)saquinavir will increase the level or effect of chloroquine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• chlorpromazine

  Monitor Closely (1)saquinavir, chlorpromazine. Either increases toxicity of the other by QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR or QT prolongation and cardiac arrhythmias.

• cholic acid

  Monitor Closely (1)saquinavir increases toxicity of cholic acid by decreasing elimination. Modify Therapy/Monitor Closely. Avoid concomitant use of inhibitors of the bile salt efflux pump (BSEP). May exacerbate accumulation of conjugated bile salts in the liver and result in clinical symptoms. If concomitant use is necessary, monitor serum transaminases and bilirubin.

• ciclesonide inhaled

  Serious - Use Alternative (1)saquinavir will increase the level or effect of ciclesonide inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• cilostazol

  Serious - Use Alternative (1)saquinavir will increase the level or effect of cilostazol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.Minor (1)saquinavir increases levels of cilostazol by decreasing metabolism. Minor/Significance Unknown.

• cimetidine

  Serious - Use Alternative (1)cimetidine will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ciprofloxacin

  Monitor Closely (1)ciprofloxacin and saquinavir both increase QTc interval. Use Caution/Monitor. Ciprofloxacin elicits minimal effects on QT interval. Caution if used in combination with other drugs known to affect QT interval or in patients with other risk factors.Serious - Use Alternative (1)saquinavir increases levels of ciprofloxacin by pharmacodynamic synergism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• cisapride

  Serious - Use Alternative (1)saquinavir increases levels of cisapride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Increased risk of QT prolongation and cardiac arrhythmias.

• citalopram

  Monitor Closely (1)saquinavir and citalopram both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended, along with drugs that may prolong the QT interval.Serious - Use Alternative (1)saquinavir will increase the level or effect of citalopram by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• clarithromycin

  Contraindicated (1)clarithromycin and saquinavir both increase QTc interval. Contraindicated.Monitor Closely (1)clarithromycin will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (2)saquinavir will increase the level or effect of clarithromycin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
  
  clarithromycin will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• clonazepam

  Monitor Closely (1)saquinavir increases levels of clonazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Use alternatives if available. Consider lowering benzodiazepine dose.

• clorazepate

  Monitor Closely (1)saquinavir increases levels of clorazepate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Use alternatives if available. Consider lowering benzodiazepine dose.

• clotrimazole

  Monitor Closely (1)clotrimazole will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• clozapine

  Contraindicated (1)clozapine and saquinavir both increase QTc interval. Contraindicated.Serious - Use Alternative (1)saquinavir increases levels of clozapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• cobicistat

  Serious - Use Alternative (3)cobicistat will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  cobicistat will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.
  
  saquinavir will increase the level or effect of cobicistat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• cobimetinib

  Contraindicated (1)saquinavir will increase the level or effect of cobimetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Avoid coadministration with strong CYP3A4 inhibitors with (increases cobimetinib systemic exposure by 6.7-fold).

• colchicine

  Serious - Use Alternative (1)saquinavir will increase the level or effect of colchicine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid use of colchicine with strong CYP3A4 inhibitors. If coadministration is necessary, decrease colchicine dose or frequency as recommended in prescribing information. Use of any colchicine product in conjunction with strong CYP3A4 inhibitors is contraindicated in patients with renal or hepatic impairment.

• conivaptan

  Contraindicated (1)saquinavir will increase the level or effect of conivaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of conivaptan with strong CYP3A4 inhibitors is contraindicated.Monitor Closely (1)conivaptan will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• conjugated estrogens

  Monitor Closely (1)saquinavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• copanlisib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of copanlisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If concomitant use with strong CYP3A inhibitors cannot be avoided, reduce copanlisib dose to 45 mg.

• cortisone

  Monitor Closely (1)cortisone will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• crizotinib

  Contraindicated (1)crizotinib and saquinavir both increase QTc interval. Contraindicated.Monitor Closely (2)saquinavir increases levels of crizotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Concomitant use of strong CYP3A inhibitors should be avoided. ECG monitoring is recommended, along with drugs that may prolong the QT interval.
  
  crizotinib increases levels of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. ECG monitoring is recommended, along with drugs that may prolong the QT interval.

• crofelemer

  Monitor Closely (1)crofelemer increases levels of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 and transporters MRP2 and OATP1A2 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.

• cyclophosphamide

  Monitor Closely (1)saquinavir will increase the level or effect of cyclophosphamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cyclosporine

  Monitor Closely (1)saquinavir increases levels of cyclosporine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• dabigatran

  Monitor Closely (1)saquinavir will increase the level or effect of dabigatran by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Atrial fibrillation: Avoid coadministering dabigatran with P-gp inhibitors if CrCl <30 mL/min. DVT/PE treatment: Avoid coadministering dabigatran with P-gp inhibitors if CrCl <50 mL/min

• dabrafenib

  Serious - Use Alternative (2)saquinavir increases levels of dabrafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  dabrafenib will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• dapsone

  Serious - Use Alternative (1)saquinavir will increase the level or effect of dapsone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• daridorexant

  Serious - Use Alternative (1)saquinavir will increase the level or effect of daridorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• darifenacin

  Monitor Closely (2)darifenacin will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• darolutamide

  Monitor Closely (1)saquinavir will increase the level or effect of darolutamide by Other (see comment). Modify Therapy/Monitor Closely. Darolutamide is a P-gp and CYP3A4 substrate. Closely monitor for increased adverse reactions and modify dose of darolutamide as needed when coadministered with drugs that are both P-gp and strong or moderate CYP3A4 inhibitors.

• darunavir

  Monitor Closely (2)darunavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darunavir and saquinavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.Serious - Use Alternative (2)saquinavir will increase the level or effect of darunavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  saquinavir decreases levels of darunavir by increasing metabolism. Avoid or Use Alternate Drug.

• dasatinib

  Contraindicated (2)saquinavir will increase the level or effect of dasatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
  
  dasatinib and saquinavir both increase QTc interval. Contraindicated.Monitor Closely (1)dasatinib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• deferasirox

  Monitor Closely (1)deferasirox will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• deflazacort

  Monitor Closely (1)saquinavir will increase the level or effect of deflazacort by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Decrease deflazacort dose to one-third of the recommended dose if coadministered with moderate or strong CYP3A4 inhibitors.

• degarelix

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

• delavirdine

  Serious - Use Alternative (1)saquinavir will increase the level or effect of delavirdine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• desflurane

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

• deutetrabenazine

  Monitor Closely (1)deutetrabenazine and saquinavir 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).

• dexamethasone

  Monitor Closely (1)dexamethasone will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of dexamethasone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• dexlansoprazole

  Monitor Closely (1)dexlansoprazole increases levels of saquinavir by unknown mechanism. Use Caution/Monitor. Potential for increased toxicity. .

• DHEA, herbal

  Monitor Closely (1)DHEA, herbal will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• diazepam

  Monitor Closely (1)saquinavir increases levels of diazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Use alternatives if available.

• diazepam intranasal

  Monitor Closely (1)saquinavir will increase the level or effect of diazepam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong or moderate CYP3A4 inhibitors may decrease rate of diazepam elimination, thereby increasing adverse reactions to diazepam.

• diazoxide

  Monitor Closely (1)saquinavir increases effects of diazoxide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• dienogest/estradiol valerate

  Monitor Closely (1)saquinavir will increase the level or effect of dienogest/estradiol valerate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Significant changes (increase or decrease) in plasma levels of estrogen and progestin have been seen when HIV protease inhibitors are administered. Monitor for potential adverse effects such as nausea, irregular uterine bleeding, breast tenderness and headache.

• digoxin

  Monitor Closely (1)saquinavir increases levels of digoxin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Potential for increased toxicity. .

• dihydroergotamine

  Contraindicated (1)saquinavir increases levels of dihydroergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• dihydroergotamine intranasal

  Contraindicated (1)saquinavir increases levels of dihydroergotamine intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• diltiazem

  Monitor Closely (2)diltiazem will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of diltiazem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• disopyramide

  Serious - Use Alternative (1)saquinavir increases levels of disopyramide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.

• docetaxel

  Monitor Closely (1)saquinavir increases levels of docetaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• dofetilide

  Contraindicated (1)dofetilide increases toxicity of saquinavir by QTc interval. Contraindicated.

• dolasetron

  Monitor Closely (1)saquinavir increases levels of dolasetron by QTc interval. Modify Therapy/Monitor Closely. Potential for increased toxicity. Increased risk of cardiac arrhythmias.

• doravirine

  Monitor Closely (1)saquinavir will increase the level or effect of doravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of doravirine and CYP3A4 inhibitors may increase plasma concentrations and toxicities of doravirine.

• doxepin

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

• doxepin cream

  Monitor Closely (1)saquinavir will increase the level or effect of doxepin cream by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• doxorubicin

  Serious - Use Alternative (1)saquinavir will increase the level or effect of doxorubicin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• doxorubicin liposomal

  Serious - Use Alternative (1)saquinavir will increase the level or effect of doxorubicin liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• dronabinol

  Monitor Closely (1)saquinavir will increase the level or effect of dronabinol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dronabinol is a CYP3A4 substrate.

• dronedarone

  Contraindicated (1)saquinavir will increase the level or effect of dronedarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Monitor Closely (1)dronedarone will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)dronedarone will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• droperidol

  Serious - Use Alternative (1)saquinavir increases levels of droperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• duvelisib

  Monitor Closely (2)saquinavir will increase the level or effect of duvelisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with a strong CYP3A4 inhibitor increases duvelisib AUC, which may increase the risk of duvelisib toxicities. Reduce duvelisib dose to 15 mg BID when coadministered with a strong CYP3A4 inhibitor.
  
  duvelisib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with duvelisib increases AUC of a sensitive CYP3A4 substrate which may increase the risk of toxicities of these drugs. Consider reducing the dose of the sensitive CYP3A4 substrate and monitor for signs of toxicities of the coadministered sensitive CYP3A substrate.

• edoxaban

  Serious - Use Alternative (1)saquinavir will increase the level or effect of edoxaban by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. Dose adjustment may be required with strong P-gp inhibitors. DVT/PE treatment: Decrease dose to 30 mg PO once daily. NVAF: No dose reduction recommended

• efavirenz

  Monitor Closely (2)efavirenz will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir and efavirenz both increase risk of immune reconstitution syndrome. Use Caution/Monitor.Serious - Use Alternative (2)saquinavir will increase the level or effect of efavirenz by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  efavirenz and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• elagolix

  Monitor Closely (3)elagolix will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of elagolix by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration of elagolix 200 mg BID with strong CYP3A inhibitors for >1 month is not recommended. Limit elagolix dose to 150 mg qDay and CYP3A inhibitor duration of use to 6 months if coadministered.
  
  elagolix decreases levels of saquinavir 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.

• elbasvir/grazoprevir

  Contraindicated (1)saquinavir increases levels of elbasvir/grazoprevir by Other (see comment). Contraindicated. Comment: Coadministration with strong OATP1B1/3 inhibitors may increase the risk of ALT elevations owing to a significant increase in grazoprevir plasma concentrations.Serious - Use Alternative (1)saquinavir will increase the level or effect of elbasvir/grazoprevir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• eletriptan

  Contraindicated (1)saquinavir increases levels of eletriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Potential for increased toxicity. Contraindicated for use within 72 hours of potent CYP3A4 inhibitors.

• eliglustat

  Contraindicated (1)saquinavir will increase the level or effect of eliglustat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inhibitors are contraindicated with eliglustat poor or intermediate metabolizers; reduce eliglustat dose from 84 mg BID to 84 mg once daily in extensive metabolizers; eliglustat is contraindiated if strong or moderate CYP2D6 inhibitors are given concomitantly with strong or moderate CYP3A inhibitorsMonitor Closely (1)eliglustat increases levels of saquinavir by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the P-gp substrate and titrate to clinical effect.Serious - Use Alternative (1)eliglustat and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• eluxadoline

  Monitor Closely (1)eluxadoline increases levels of saquinavir by decreasing metabolism. Use Caution/Monitor. Eluxadoline may increase the systemic exposure of coadministered OATP1B1 substrates.Serious - Use Alternative (1)saquinavir increases levels of eluxadoline by decreasing metabolism. Avoid or Use Alternate Drug. Decrease eluxadoline dose to 75 mg PO BID if coadministered with OATP1B1 inhibitors. .

• elvitegravir

  Monitor Closely (1)saquinavir increases levels of elvitegravir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Elvitegravir is a CYP3A4 substrate; if coadministered with strong CYP3A4 inhibitors may increase levels.

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  Contraindicated (2)saquinavir, elvitegravir/cobicistat/emtricitabine/tenofovir DF. Other (see comment). Contraindicated. Comment: Elvitegravir/cobicistat/emtricitabine/tenofovir is a complete regimen for HIV and should not be administered with other antiretrovirals.
  
  saquinavir will increase the level or effect of elvitegravir/cobicistat/emtricitabine/tenofovir DF by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• emtricitabine

  Monitor Closely (1)saquinavir and emtricitabine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• encorafenib

  Monitor Closely (1)encorafenib, saquinavir. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.Serious - Use Alternative (2)saquinavir will increase the level or effect of encorafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If concomitant use of a strong CYP3A4 inhibitor is unavoidable, reduce encorafenib dose to one-third of the dose (eg, reduce from 450 mg/day to 150 mg/day). After discontinuing the inhibitor for 3-5 elimination half-lives, resume previous encorafenib dose.
  
  encorafenib and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• enfortumab vedotin

  Monitor Closely (1)saquinavir increases toxicity of enfortumab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Enfortumab vedotin is an antibody-drug conjugate that releases monomethylauristatin E (MMAE) via proteolytic cleavage. MMAE is primarily metabolized by CYP3A4 in vitro. Coadministration with strong CYP3A4 inhibitors may increase free MMAE exposure, which may increase the incidence or severity of toxicities.

• enfuvirtide

  Monitor Closely (1)saquinavir and enfuvirtide both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• entrectinib

  Serious - Use Alternative (2)saquinavir and entrectinib both increase QTc interval. Avoid or Use Alternate Drug.
  
  saquinavir will increase the level or effect of entrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of strong CYP3A4 inhibitors with entrectinib, a CYP3A4 substrate. If coadministration unavoidable, reduce entrectinib dose to 100 mg/day for patients aged 12 y or older with BSA >1.50m2. Resume previous entrectinib dose after discontinuing strong CYP3A inhibitor for 3-5 elimination half-lives.

• enzalutamide

  Serious - Use Alternative (2)saquinavir will increase the level or effect of enzalutamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  enzalutamide will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• eplerenone

  Contraindicated (1)saquinavir increases levels of eplerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Potential for increased toxicity. .

• erdafitinib

  Serious - Use Alternative (2)saquinavir will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.
  
  erdafitinib will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

• ergoloid mesylates

  Contraindicated (1)saquinavir will increase the level or effect of ergoloid mesylates by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Serious - Use Alternative (1)saquinavir increases levels of ergoloid mesylates by decreasing metabolism. Contraindicated.

• ergonovine

  Contraindicated (1)saquinavir will increase the level or effect of ergonovine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• ergotamine

  Serious - Use Alternative (2)saquinavir increases levels of ergotamine by decreasing metabolism. Contraindicated.
  
  saquinavir will increase the level or effect of ergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• eribulin

  Serious - Use Alternative (1)eribulin and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. Potential for enhanced QTc-prolonging effects; if concurrent use is necessary then ECG monitoring is recommended.

• erlotinib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of erlotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin base

  Contraindicated (1)saquinavir will increase the level or effect of erythromycin base by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Monitor Closely (1)erythromycin base will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)erythromycin base will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin ethylsuccinate

  Contraindicated (1)saquinavir will increase the level or effect of erythromycin ethylsuccinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Monitor Closely (1)erythromycin ethylsuccinate will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)erythromycin ethylsuccinate will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin lactobionate

  Contraindicated (1)saquinavir will increase the level or effect of erythromycin lactobionate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Monitor Closely (1)erythromycin lactobionate will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)erythromycin lactobionate will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin stearate

  Contraindicated (1)saquinavir will increase the level or effect of erythromycin stearate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Monitor Closely (1)erythromycin stearate will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)erythromycin stearate will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• escitalopram

  Serious - Use Alternative (2)saquinavir will increase the level or effect of escitalopram by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  escitalopram increases toxicity of saquinavir by QTc interval. Avoid or Use Alternate Drug.

• eslicarbazepine acetate

  Monitor Closely (1)eslicarbazepine acetate will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• esmolol

  Monitor Closely (1)saquinavir, esmolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• estradiol vaginal

  Monitor Closely (1)saquinavir will increase the level or effect of estradiol vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration with CYP3A4 inhibitors may increase plasma concentrations of estrogens and toxicities.

• eszopiclone

  Monitor Closely (1)saquinavir increases levels of eszopiclone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce eszopiclone starting dose to 1 mg/day.

• ethinylestradiol

  Serious - Use Alternative (2)saquinavir will increase the level or effect of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  saquinavir, ethinylestradiol. Other (see comment). Avoid or Use Alternate Drug. Comment: Significant changes (increase or decrease) can occur in estrogen plasma levels. Efficacy of hormonal contraceptives may be reduced. Use of a nonhormonal contraceptive is recommended. .

• ethosuximide

  Monitor Closely (1)saquinavir increases levels of ethosuximide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• etravirine

  Monitor Closely (2)etravirine will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of etravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• everolimus

  Serious - Use Alternative (1)saquinavir will increase the level or effect of everolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• exenatide injectable solution

  Monitor Closely (1)saquinavir decreases effects of exenatide injectable solution by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• exenatide injectable suspension

  Monitor Closely (1)saquinavir decreases effects of exenatide injectable suspension by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors.

• ezogabine

  Monitor Closely (1)ezogabine, saquinavir. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Slight and transient QT-prolongation observed with ezogabine, particularly when dose titrated to 1200 mg/day. QT interval should be monitored when ezogabine is prescribed with agents known to increase QT interval.

• famotidine

  Monitor Closely (1)famotidine will increase the level or effect of saquinavir by unspecified interaction mechanism. Use Caution/Monitor.

• fedratinib

  Monitor Closely (1)fedratinib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (2)saquinavir will increase the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid fedratinib coadministration with strong CYP3A4 inhibitors, decrease fedratinib dose to 200 mg/day. If CYP3A4 inhibitor discontinued, increase fedratinib dose to 300 mg/day for 2 weeks, and then 400 mg/day thereafter as tolerated.
  
  saquinavir will increase the level or effect of fedratinib by Other (see comment). Avoid or Use Alternate Drug. Avoid coadministration of fedratinib (a CYP3A4 and CYP2C19 substrate) with dual CYP3A4 and CYP2C19 inhibitor. Effect of coadministration of a dual CYP3A4 and CYP2C19 inhibitor with fedratinib has not been studied.

• felbamate

  Serious - Use Alternative (1)saquinavir will increase the level or effect of felbamate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• felodipine

  Monitor Closely (2)felodipine will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  saquinavir increases levels of felodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• fentanyl

  Serious - Use Alternative (1)saquinavir will increase the level or effect of fentanyl by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fentanyl intranasal

  Serious - Use Alternative (1)saquinavir will increase the level or effect of fentanyl intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fentanyl transdermal

  Serious - Use Alternative (1)saquinavir will increase the level or effect of fentanyl transdermal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fentanyl transmucosal

  Serious - Use Alternative (1)saquinavir will increase the level or effect of fentanyl transmucosal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of CYP3A4 inhibitors with fentanyl is necessary, monitor patients for respiratory depression and sedation at frequent intervals and consider fentanyl dose adjustments until stable drug effects are achieved.

• fexinidazole

  Serious - Use Alternative (3)saquinavir will decrease the level or effect of fexinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration, monitor fexinidazole for decreased efficacy owing to decreased plasma concentrations of active M1 and M2 metabolites.
  
  fexinidazole and saquinavir 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 saquinavir 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.

• finerenone

  Contraindicated (1)saquinavir will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• fingolimod

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

• flecainide

  Monitor Closely (1)saquinavir increases levels of flecainide by QTc interval. Modify Therapy/Monitor Closely. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• flibanserin

  Contraindicated (1)saquinavir will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of flibanserin with moderate or strong CYP3A4 inhibitors is contraindicated. Severe hypotension or syncope can occur.

• fluconazole

  Monitor Closely (1)fluconazole will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fludrocortisone

  Monitor Closely (1)fludrocortisone will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• flunisolide inhaled

  Monitor Closely (1)saquinavir will increase the level or effect of flunisolide inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fluoxetine

  Monitor Closely (1)saquinavir and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.

• fluphenazine

  Serious - Use Alternative (1)saquinavir increases levels of fluphenazine by QTc interval. Avoid or Use Alternate Drug. Potential for increased toxicity. .

• flurazepam

  Monitor Closely (1)saquinavir increases levels of flurazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Use alternatives if available. Consider lowering benzodiazepine dose.

• fluticasone furoate

  Monitor Closely (1)saquinavir will increase the level or effect of fluticasone furoate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inhibitors may increase fluticasone systemic exposure

• fluticasone inhaled

  Monitor Closely (1)saquinavir will increase the level or effect of fluticasone inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inhibitors may increase fluticasone systemic exposure

• fluticasone intranasal

  Serious - Use Alternative (1)saquinavir will increase the level or effect of fluticasone intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Strong CYP3A4 inhibitors may increase systemic corticosteroid adverse effects; monitor for signs/symptoms of high corticosteroid concentrations including Cushing type signs/symptoms.

• fluvastatin

  Monitor Closely (1)saquinavir increases toxicity of fluvastatin by Other (see comment). Use Caution/Monitor. Comment: OATP1B1 inhibitors may increase risk of myopathy.

• fluvoxamine

  Monitor Closely (1)fluvoxamine will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• food

  Minor (1)food increases levels of saquinavir by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• fosamprenavir

  Monitor Closely (3)fosamprenavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  fosamprenavir and saquinavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• fosphenytoin

  Monitor Closely (2)fosphenytoin will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  fosphenytoin will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• fostamatinib

  Monitor Closely (1)saquinavir will increase the level or effect of fostamatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong CYP3A4 inhibitors may increase exposure to R406 (fostamatinib major active metabolite). Monitor for toxicities that may require fostamatinib dose reduction.

• fostemsavir

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

• gadobenate

  Contraindicated (1)gadobenate and saquinavir both increase QTc interval. Contraindicated.

• ganaxolone

  Minor (1)saquinavir, ganaxolone. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. Changes in ganaxolone exposures when coadministered with strong, moderate, or weak CYP3A4 inhibitors are not expected to be clinically significant.

• garlic

  Monitor Closely (1)garlic decreases levels of saquinavir by unknown mechanism. Use Caution/Monitor.

• gefitinib

  Monitor Closely (1)saquinavir increases levels of gefitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration of strong CYP3A4 inhibitors may increase risk for gefitinib adverse effects.

• gemifloxacin

  Serious - Use Alternative (2)saquinavir increases levels of gemifloxacin by QTc interval. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.
  
  saquinavir increases levels of gemifloxacin by pharmacodynamic synergism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• gemtuzumab

  Monitor Closely (1)saquinavir and gemtuzumab both increase QTc interval. Use Caution/Monitor.

• gilteritinib

  Contraindicated (1)gilteritinib and saquinavir both increase QTc interval. Contraindicated.Serious - Use Alternative (1)saquinavir will increase the level or effect of gilteritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Consider alternatives to any strong CYP3A4 inhibitor when coadministered with gilteritinib. If such a combination cannot be avoided, closely monitor for gilteritinib-related adverse effects. Interrupt and reduce gilteritinib dosage in patients with serious or life-threatening toxicity.

• glasdegib

  Serious - Use Alternative (2)saquinavir will increase the level or effect of glasdegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Consider alternate therapies that are not strong CYP3A inhibitors or monitor for increased risk of adverse effects, including QTc interval prolongation.
  
  saquinavir and glasdegib both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, monitor for increased risk of QTc interval prolongation.

• glecaprevir/pibrentasvir

  Monitor Closely (3)saquinavir will increase the level or effect of glecaprevir/pibrentasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of glecaprevir/pibrentasvir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  glecaprevir/pibrentasvir will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• glimepiride

  Monitor Closely (1)saquinavir decreases effects of glimepiride by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• glipizide

  Monitor Closely (1)saquinavir decreases effects of glipizide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• glyburide

  Monitor Closely (1)saquinavir decreases effects of glyburide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• goserelin

  Monitor Closely (1)goserelin increases toxicity of saquinavir by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• granisetron

  Serious - Use Alternative (1)saquinavir increases levels of granisetron by QTc interval. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• grapefruit

  Monitor Closely (1)grapefruit will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• griseofulvin

  Monitor Closely (1)griseofulvin will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• guanfacine

  Monitor Closely (1)saquinavir will increase the level or effect of guanfacine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong or moderate CYP3A4 inhibitors significantly increase guanfacine plasma concentrations. FDA-approved labeling for extended-release (ER) guanfacine recommends that, if coadministered, the guanfacine dosage should be decreased to half of the recommended dose. Specific recommendations for immediate-release (IR) guanfacine are not available.

• haloperidol

  Serious - Use Alternative (2)saquinavir increases levels of haloperidol by QTc interval. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.
  
  saquinavir increases levels of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• histrelin

  Monitor Closely (1)histrelin increases toxicity of saquinavir by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• hydrocodone

  Monitor Closely (1)saquinavir will increase the level or effect of hydrocodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with CYP3A4 inhibitors may increase hydrocodone plasma concentrations and can result in potentially fatal respiratory depression

• hydrocortisone

  Monitor Closely (1)hydrocortisone will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• hydroxychloroquine sulfate

  Serious - Use Alternative (1)hydroxychloroquine sulfate and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• hydroxyprogesterone caproate

  Serious - Use Alternative (1)saquinavir will increase the level or effect of hydroxyprogesterone caproate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• hydroxyzine

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

• ibrutinib

  Serious - Use Alternative (1)saquinavir increases levels of ibrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of ibrutinib and strong CYP3A4 inhibitors. If a strong CYP3A4 inhibitor must be used short-term (eg, anti-infectives for =7 days), interrupt ibrutinib therapy until strong CYP3A4 inhibitor is discontinued.

• ibuprofen/famotidine

  Monitor Closely (1)ibuprofen/famotidine will increase the level or effect of saquinavir by unspecified interaction mechanism. Use Caution/Monitor.

• ibutilide

  Monitor Closely (1)saquinavir increases toxicity of ibutilide by QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of QT prolongation and cardiac arrhythmias.

• idelalisib

  Serious - Use Alternative (2)saquinavir will increase the level or effect of idelalisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministered with strong CYP3A inhibitors, monitor for signs of idelalisib toxicity; follow recommendations for dosage modifications if adverse reactions occur
  
  idelalisib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates

• ifosfamide

  Monitor Closely (1)saquinavir will decrease the level or effect of ifosfamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of CYP3A4 inhibitors may decrease the metabolism of ifosfamide to its active alkylating metabolites and decrease the efficacy of ifosfamide.

• iloperidone

  Monitor Closely (2)saquinavir increases levels of iloperidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.
  
  iloperidone increases levels of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.

• imatinib

  Monitor Closely (1)saquinavir will increase the level or effect of imatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• indacaterol, inhaled

  Monitor Closely (2)indacaterol, inhaled, saquinavir. QTc interval. Use Caution/Monitor. Drugs that are known to prolong the QTc interval may have an increased the risk of ventricular arrhythmias.
  
  saquinavir increases levels of indacaterol, inhaled by Other (see comment). Use Caution/Monitor. Comment: Data suggests that systemic clearance is influenced by modulation of both P-gp and CYP3A4 activities. No dose adjustment is warranted at the 75 mcg dose.

• indinavir

  Monitor Closely (3)indinavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  indinavir will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  indinavir and saquinavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of indinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• infigratinib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of infigratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• inotuzumab

  Serious - Use Alternative (1)inotuzumab and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. If unable to avoid concomitant use, obtain ECGs and electrolytes before and after initiation of any drug known to prolong QTc, and periodically monitor as clinically indicated during treatment.

• insulin aspart

  Monitor Closely (1)saquinavir decreases effects of insulin aspart by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• insulin degludec

  Monitor Closely (1)saquinavir decreases effects of insulin degludec by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. HIV protease inhibitors may cause new onset diabetes mellitus (DM), exacerbate existing DM, and cause hyperglycemia due to insulin resistance.

• insulin degludec/insulin aspart

  Monitor Closely (1)saquinavir decreases effects of insulin degludec/insulin aspart by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. HIV protease inhibitors may cause new onset diabetes mellitus (DM), exacerbate existing DM, and cause hyperglycemia due to insulin resistance.

• insulin detemir

  Monitor Closely (1)saquinavir decreases effects of insulin detemir by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• insulin glargine

  Monitor Closely (1)saquinavir decreases effects of insulin glargine by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• insulin glulisine

  Monitor Closely (1)saquinavir decreases effects of insulin glulisine by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• insulin inhaled

  Monitor Closely (1)saquinavir decreases effects of insulin inhaled by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. HIV protease inhibitors may cause new onset diabetes mellitus (DM), exacerbate existing DM, and cause hyperglycemia due to insulin resistance.

• insulin lispro

  Monitor Closely (1)saquinavir decreases effects of insulin lispro by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• insulin NPH

  Monitor Closely (1)saquinavir decreases effects of insulin NPH by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• insulin regular human

  Monitor Closely (1)saquinavir decreases effects of insulin regular human by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• irinotecan

  Serious - Use Alternative (1)saquinavir will increase the level or effect of irinotecan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• irinotecan liposomal

  Serious - Use Alternative (1)saquinavir will increase the level or effect of irinotecan liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• isavuconazonium sulfate

  Contraindicated (1)saquinavir will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• isoflurane

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

• isoniazid

  Monitor Closely (1)isoniazid will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• isradipine

  Monitor Closely (1)saquinavir increases levels of isradipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• istradefylline

  Monitor Closely (3)istradefylline will increase the level or effect of saquinavir 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.
  
  istradefylline will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of P-gp substrates in clinical trials. Consider dose reduction of sensitive P-gp substrates.
  
  saquinavir will increase the level or effect of istradefylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Do not exceed istradefylline 20 mg/day if coadministered with strong CYP3A4 inhibitors.

• itraconazole

  Monitor Closely (2)itraconazole will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Limit itraconazole dose to 200 mg/day in patients receiving saquinavir/ritonavir.
  
  itraconazole will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Limit itraconazole dose to 200 mg/day in patients receiving saquinavir/ritonavir.Serious - Use Alternative (2)saquinavir will increase the level or effect of itraconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  itraconazole and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• ivabradine

  Contraindicated (1)saquinavir will increase the level or effect of ivabradine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of ivabradine with strong CYP3A4 inhibitors is contraindicated.

• ivacaftor

  Monitor Closely (2)ivacaftor increases levels of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Ivacaftor and its M1 metabolite has the potential to inhibit P-gp; may significantly increase systemic exposure to sensitive P-gp substrates with a narrow therapeutic index.
  
  saquinavir will increase the level or effect of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce ivacaftor dose if coadministered with strong CYP3A4 inhibitors. See specific ivacaftor-containing product for precise dosage modification.

• ivosidenib

  Serious - Use Alternative (3)saquinavir will increase the level or effect of ivosidenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of strong CYP3A4 inhibitors with ivosidenib or replace with alternate therapies. If coadministration of a strong CYP3A4 inhibitor is unavoidable, reduce ivosidenib dose to 250 mg qDay. If the strong inhibitor is discontinued, increase ivosidenib dose (after at least 5 half-lives of the strong CYP3A4 inhibitor) to the recommended dose of 500 mg qDay. Monitor for increased risk of QTc interval prolongation.
  
  ivosidenib and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of QTc prolonging drugs with ivosidenib or replace with alternate therapies. If coadministration of a QTc prolonging drug is unavoidable, monitor for increased risk of QTc interval prolongation.
  
  ivosidenib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternative therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.

• ixabepilone

  Serious - Use Alternative (1)saquinavir will increase the level or effect of ixabepilone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ixazomib

  Minor (1)saquinavir, ixazomib. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. In clinical trials, coadministration of ixazomib with strong CYP3A inhibitors did not result in a clinically meaningful change in the systemic exposure of ixazomib.

• ketamine

  Monitor Closely (1)saquinavir will decrease the level or effect of ketamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ketoconazole

  Monitor Closely (1)ketoconazole will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)ketoconazole will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• labetalol

  Monitor Closely (1)saquinavir, labetalol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR or QT prolongation and cardiac arrhythmias.

• lacosamide

  Monitor Closely (2)saquinavir increases levels of lacosamide by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Potential for increased toxicity. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.
  
  saquinavir increases levels of lacosamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Consider decreasing lacosamide dose when coadministered with strong CYP3A4 inhibitors.

• lamivudine

  Monitor Closely (1)saquinavir and lamivudine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• lansoprazole

  Monitor Closely (1)lansoprazole increases levels of saquinavir by unknown mechanism. Use Caution/Monitor. Potential for increased toxicity. .

• lapatinib

  Monitor Closely (2)lapatinib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  lapatinib will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of lapatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• larotrectinib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of larotrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of larotrectinib with strong CYP3A4 inhibitors is unavoidable, reduce larotrectinib dose by 50%. Resume prior larotrectinib dose once CYP3A4 inhibitor discontinued for 3-5 half-lives.

• lasmiditan

  Serious - Use Alternative (1)lasmiditan increases levels of saquinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• lefamulin

  Contraindicated (1)lefamulin will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Lefamulin is contraindicated with CYP3A substrates know to prolong the QT interval.Serious - Use Alternative (1)saquinavir will increase the level or effect of lefamulin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of lefamulin with strong CYP3A inhibitors.

• lemborexant

  Serious - Use Alternative (1)saquinavir will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of lemborexant with moderate or strong CYP3A inhibitors.

• lenvatinib

  Monitor Closely (1)saquinavir and lenvatinib both increase QTc interval. Use Caution/Monitor. Lenvatinib prescribing information recommends monitoring ECG closely when coadministered with QT prolonging drugs.

• letermovir

  Monitor Closely (2)saquinavir increases levels of letermovir by decreasing metabolism. Use Caution/Monitor. Coadminstration of letermovir, an OATP1B1/3 substrate, with OATP1B1/3 inhibitors may increase letermovir plasma concentrations.
  
  letermovir increases levels of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• leuprolide

  Monitor Closely (1)leuprolide increases toxicity of saquinavir by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• levalbuterol

  Monitor Closely (1)levalbuterol, saquinavir. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Increased risk of hypokalemia, QT prolongation, and cardiac arrhythmias.

• levamlodipine

  Monitor Closely (1)saquinavir will increase the level or effect of levamlodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with moderate and strong CYP3A inhibitors results in increased systemic exposure to amlodipine and may require dose reduction. Monitor for symptoms of hypotension and edema when amlodipine is coadministered with CYP3A inhibitors to determine the need for dose adjustment.

• levobunolol

  Monitor Closely (1)saquinavir, levobunolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• levofloxacin

  Serious - Use Alternative (1)saquinavir increases levels of levofloxacin by QTc interval. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• levoketoconazole

  Monitor Closely (1)levoketoconazole will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)levoketoconazole will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• levomilnacipran

  Monitor Closely (1)saquinavir will increase the level or effect of levomilnacipran by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Do not exceed 80 mg/day of levomilnacipran when coadministered with strong CYP3A4 inhibitors

• levonorgestrel oral/ethinylestradiol/ferrous bisglycinate

  Serious - Use Alternative (1)saquinavir, levonorgestrel oral/ethinylestradiol/ferrous bisglycinate. Other (see comment). Avoid or Use Alternate Drug. Comment: Significant changes (increase or decrease) can occur in estrogen plasma levels. Efficacy of hormonal contraceptives may be reduced. Use of a nonhormonal contraceptive is recommended.

• linagliptin

  Monitor Closely (2)saquinavir decreases effects of linagliptin by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .
  
  saquinavir will increase the level or effect of linagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• liraglutide

  Monitor Closely (1)saquinavir decreases effects of liraglutide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• lithium

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

• lomitapide

  Contraindicated (1)saquinavir increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Increases lomitapide levels several folds.Monitor Closely (1)lomitapide increases levels of saquinavir by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Consider reducing dose when used concomitantly with lomitapide.

• lonafarnib

  Contraindicated (1)saquinavir will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Lonafarnib is a sensitive CYP3A4 substrate. Coadministration with strong or moderate CYP3A4 inhibitors is contraindicated.

• lopinavir

  Monitor Closely (1)lopinavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of lopinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• loratadine

  Monitor Closely (1)loratadine will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• lorlatinib

  Serious - Use Alternative (2)lorlatinib will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  saquinavir will increase the level or effect of lorlatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministering lorlatinib with strong CYP3A inhibitors. If unavoidable, reduce lorlatinib dose by 25 mg/day. If strong CYP3A inhibitor discontinued, increase to previous lorlatinib (dose after 3 plasma half-lives of strong CYP3A inhibitor). See monograph for further details.

• lovastatin

  Contraindicated (2)lovastatin will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Contraindicated.
  
  saquinavir increases levels of lovastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inhibitors increase systemic statin exposure and risk of myopathy, including rhabdomyolysis.

• lumacaftor/ivacaftor

  Monitor Closely (1)saquinavir increases levels of lumacaftor/ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong CYP3A inhibitors do not impact lumacaftor exposure, but increased ivacaftor exposure by 4.3-fold. Due to the induction effect of lumacaftor on CYP3A, at steady-state the net exposure of ivacaftor is not expected to exceed that when given in the absence of lumacaftor at a dose of 150 mg q12hr (the approved dose of ivacaftor monotherapy). Therefore, no dose adjustment is necessary when CYP3A inhibitors are initiated in patients currently taking lumacaftor/ivacaftor. However, when initiating lumacaftor/ivacaftor in patients taking strong CYP3A inhibitors, reduce the dose to 1 tablet daily (lumacaftor 200 mg/ivacaftor 125 mg total daily dose) for the first week of treatment to allow for the steady-state induction effect of lumacaftor. Following this period, continue with the recommended daily dose. No dose adjustment is required for moderate or weak CYP3A4 inhibitors.

• lumateperone

  Monitor Closely (1)saquinavir will increase the level or effect of lumateperone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce lumateperone dose to 10.5 mg/day if coadministered with strong CYP3A4 inhibitors.

• lumefantrine

  Monitor Closely (1)lumefantrine will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir increases levels of lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• lurasidone

  Contraindicated (1)saquinavir increases levels of lurasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of lurasidone and strong CYP3A4 inhibitors is contraindicated.

• lurbinectedin

  Serious - Use Alternative (1)saquinavir will increase the level or effect of lurbinectedin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• macimorelin

  Serious - Use Alternative (2)saquinavir will increase the level or effect of macimorelin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  macimorelin and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. Macimorelin causes an increase of ~11 msec in the corrected QT interval. Avoid coadministration with drugs that prolong QT interval, which could increase risk for developing torsade de pointes-type ventricular tachycardia. Allow sufficient washout time of drugs that are known to prolong the QT interval before administering macimorelin.

• macitentan

  Serious - Use Alternative (1)saquinavir will increase the level or effect of macitentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministering macitentan with strong CYP3A4 inhibitors

• maraviroc

  Monitor Closely (1)saquinavir increases levels of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. Adjust maraviroc dose to 150mg BID.

• marijuana

  Monitor Closely (2)marijuana will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of marijuana by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• mavacamten

  Contraindicated (1)saquinavir will increase the level or effect of mavacamten by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inhibitors may increase mavacamten systemic exposure, resulting in heart failure due to systolic dysfunction. Monitor Closely (1)saquinavir will increase the level or effect of mavacamten by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Inititiation of weak CYP2C19 inhibitors may require decreased mavacamten dose.

• medroxyprogesterone

  Serious - Use Alternative (1)saquinavir will increase the level or effect of medroxyprogesterone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• mefloquine

  Serious - Use Alternative (1)saquinavir increases levels of mefloquine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Avoid coadministration during and for 15 weeks after discontinuing mefloquine. .

• mestranol

  Serious - Use Alternative (1)saquinavir will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• metformin

  Monitor Closely (1)saquinavir decreases effects of metformin by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• methadone

  Serious - Use Alternative (2)saquinavir, methadone. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Increased risk of PR prolongation and cardiac arrhythmias.
  
  saquinavir will increase the level or effect of methadone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• methylergonovine

  Serious - Use Alternative (2)saquinavir increases levels of methylergonovine by decreasing metabolism. Contraindicated.
  
  saquinavir will increase the level or effect of methylergonovine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• methylprednisolone

  Monitor Closely (2)methylprednisolone will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of methylprednisolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• metoprolol

  Monitor Closely (1)saquinavir, metoprolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• metronidazole

  Monitor Closely (1)metronidazole will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• miconazole vaginal

  Monitor Closely (1)miconazole vaginal will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• midazolam

  Serious - Use Alternative (2)saquinavir will increase the level or effect of midazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  saquinavir increases levels of midazolam by decreasing metabolism. Contraindicated.

• midazolam intranasal

  Serious - Use Alternative (1)saquinavir will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of strong CYP3A4 inhibitors with midazolam intranasal causes higher midazolam systemic exposure, which may prolong sedation.

• midostaurin

  Serious - Use Alternative (1)saquinavir will increase the level or effect of midostaurin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong CYP3A4 inhibitors cannot be avoided, monitor midostaurin for increased risk of adverse reactions, especially during the first week of treatment.

• mifepristone

  Monitor Closely (1)saquinavir will increase the level or effect of mifepristone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Do not exceed mifepristone 300 mg/day for Cushing syndrome when coadministered with strong CYP3A4 inhibitors; combination may also prolong QT interval. Use alternatives if availableSerious - Use Alternative (1)mifepristone will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• miglitol

  Monitor Closely (1)saquinavir decreases effects of miglitol by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• mipomersen

  Monitor Closely (1)mipomersen, saquinavir. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Both drugs have potential to increase hepatic enzymes; monitor LFTs.

• mirtazapine

  Monitor Closely (2)saquinavir will increase the level or effect of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  mirtazapine and saquinavir both increase QTc interval. Use Caution/Monitor.

• mitotane

  Monitor Closely (1)mitotane decreases levels of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.

• mobocertinib

  Serious - Use Alternative (2)saquinavir will increase the level or effect of mobocertinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  mobocertinib and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, reduce mobocertinib dose and monitor QTc interval more frequently.

• modafinil

  Monitor Closely (2)saquinavir will increase the level or effect of modafinil by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available.
  
  saquinavir will increase the level or effect of modafinil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• mometasone inhaled

  Monitor Closely (1)saquinavir will increase the level or effect of mometasone inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increases riak for systemic corticosteroid side effects

• mometasone, intranasal

  Monitor Closely (1)saquinavir will increase the level or effect of mometasone, intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• moxifloxacin

  Serious - Use Alternative (1)saquinavir increases levels of moxifloxacin by QTc interval. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• nadolol

  Monitor Closely (1)saquinavir, nadolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• nafcillin

  Monitor Closely (1)nafcillin will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• naldemedine

  Monitor Closely (2)saquinavir increases levels of naldemedine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor naldemedine for potential adverse effects if coadministered with strong or moderate CYP3A4 inhibitors.
  
  saquinavir increases levels of naldemedine by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor naldemedine for potential adverse effects if coadministered with P-gp inhibitors.

• naloxegol

  Contraindicated (1)saquinavir will increase the level or effect of naloxegol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of naloxegol with strong CYP3A4 inhibitors can significantly increase naloxegol systemic exposure which may precipitate opioid withdrawal symptoms

• nateglinide

  Monitor Closely (1)saquinavir decreases effects of nateglinide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• nebivolol

  Monitor Closely (1)saquinavir, nebivolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• nefazodone

  Monitor Closely (2)nefazodone will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nefazodone will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• nelfinavir

  Monitor Closely (2)nelfinavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nelfinavir and saquinavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of nelfinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• neratinib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of neratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of neratinib with strong/moderate CYP3A4 inhibitors.

• netupitant/palonosetron

  Monitor Closely (1)saquinavir will increase the level or effect of netupitant/palonosetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Netupitant is mainly metabolized by CYP3A4; no dosage adjustment is required

• nevirapine

  Monitor Closely (2)nevirapine will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir and nevirapine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of nevirapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• nicardipine

  Monitor Closely (2)nicardipine will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  saquinavir increases levels of nicardipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• nifedipine

  Monitor Closely (3)nifedipine will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nifedipine will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  saquinavir increases levels of nifedipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. Consider initiating nifedipine at the lowest dose available if given concomitantly with this medication.

• nilotinib

  Monitor Closely (2)nilotinib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nilotinib will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of nilotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• nimodipine

  Monitor Closely (1)saquinavir increases levels of nimodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• nintedanib

  Monitor Closely (1)saquinavir increases levels of nintedanib by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. If nintedanib adverse effects occur, management may require interruption, dose reduction, or discontinuation of therapy .

• nirmatrelvir

  Monitor Closely (1)nirmatrelvir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Patients on ritonavir- or cobicistat-containing HIV regimens should continue their treatment as indicated. Monitor for increased nirmatrelvir/ritonavir or protease inhibitor adverse events with concomitant use.

• nirmatrelvir/ritonavir

  Monitor Closely (1)nirmatrelvir/ritonavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Patients on ritonavir- or cobicistat-containing HIV regimens should continue their treatment as indicated. Monitor for increased nirmatrelvir/ritonavir or protease inhibitor adverse events with concomitant use.

• nisoldipine

  Monitor Closely (1)saquinavir increases levels of nisoldipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• nizatidine

  Monitor Closely (1)nizatidine will increase the level or effect of saquinavir by unspecified interaction mechanism. Use Caution/Monitor.

• ofloxacin

  Monitor Closely (1)saquinavir increases levels of ofloxacin by QTc interval. Modify Therapy/Monitor Closely. Potential for increased toxicity. Use alternatives if available. Increased risk of QT prolongation and cardiac arrhythmias.

• olanzapine

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

• olaparib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of olaparib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong CYP3A inhibitors cannot be avoided, reduce olaparib dose to 150 mg (capsule) or 100 mg (tablet) PO BID. Do not substitute tablets with capsules.

• oliceridine

  Monitor Closely (1)saquinavir will increase the level or effect of oliceridine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If concomitant use is necessary, may require less frequent oliceridine dosing. Closely monitor for respiratory depression and sedation and titrate subsequent doses accordingly. If inhibitor is discontinued, consider increase oliceridine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal.

• olodaterol inhaled

  Monitor Closely (1)saquinavir and olodaterol inhaled both increase QTc interval. Use Caution/Monitor. Drugs that prolong the QTc interval and may potentiate the effects of beta2 agonists on the cardiovascular system; increased risk of ventricular arrhythmias

• ombitasvir/paritaprevir/ritonavir

  Serious - Use Alternative (1)saquinavir will increase the level or effect of ombitasvir/paritaprevir/ritonavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC)

  Serious - Use Alternative (1)saquinavir will increase the level or effect of ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ondansetron

  Serious - Use Alternative (2)ondansetron and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.
  
  saquinavir will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• orlistat

  Monitor Closely (1)orlistat will decrease the level or effect of saquinavir by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Loss of virological control reported in HIV-infected patients taking orlistat concomitantly. Exact mechanism is unclear, but may include a drug-drug interaction that inhibits systemic absorption of the antiretroviral drug. Monitor HIV RNA levels frequently and if increased HIV viral load confirmed, discontinue orlistat.

• osilodrostat

  Monitor Closely (2)osilodrostat and saquinavir both increase QTc interval. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of osilodrostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce dose of osilodrostat, a CYP3A4 substrate, by half when coadministered with a strong CYP3A4 inhibitor.

• osimertinib

  Monitor Closely (1)osimertinib and saquinavir both increase QTc interval. Use Caution/Monitor. Conduct periodic monitoring with ECGs and electrolytes in patients taking drugs known to prolong the QTc interval.Serious - Use Alternative (1)saquinavir will increase the level or effect of osimertinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of osimertinib with strong CYP3A4 inhibitors. If no other alternative treatment exists, monitor patient more closely for adverse effects.

• ospemifene

  Monitor Closely (1)saquinavir increases levels of ospemifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• oxaliplatin

  Monitor Closely (1)oxaliplatin will increase the level or effect of saquinavir by Other (see comment). Use Caution/Monitor. Monitor for ECG changes if therapy is initiated in patients with drugs known to prolong QT interval.Serious - Use Alternative (1)oxaliplatin and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• oxcarbazepine

  Monitor Closely (1)oxcarbazepine will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• oxycodone

  Serious - Use Alternative (1)saquinavir increases levels of oxycodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Oxycodone dose reduction may be warranted when coadministered with strong CYP3A4 inhibitors.

• ozanimod

  Monitor Closely (1)ozanimod and saquinavir both increase QTc interval. Modify Therapy/Monitor Closely. The potential additive effects on heart rate, treatment with ozanimod should generally not be initiated in patients who are concurrently treated with QT prolonging drugs with known arrhythmogenic properties.

• paclitaxel

  Monitor Closely (1)saquinavir will increase the level or effect of paclitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)saquinavir increases levels of paclitaxel by decreasing metabolism. Minor/Significance Unknown.

• paclitaxel protein bound

  Monitor Closely (1)saquinavir will increase the level or effect of paclitaxel protein bound by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)saquinavir increases levels of paclitaxel protein bound by decreasing metabolism. Minor/Significance Unknown.

• pacritinib

  Contraindicated (1)saquinavir will increase the level or effect of pacritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• palbociclib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of palbociclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of palbociclib with strong CYP3A inhibitors. If unable to avoid, reduce palbociclib dose to 75 mg/day.

• paliperidone

  Serious - Use Alternative (1)saquinavir, paliperidone. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.

• panobinostat

  Monitor Closely (1)saquinavir increases levels of panobinostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce panobinostat starting dose to 10 mg if coadministered with strong CYP3A4 inhibitors.Serious - Use Alternative (1)saquinavir and panobinostat both increase QTc interval. Avoid or Use Alternate Drug. Panobinostat is known to significantly prolong QT interval. Panobinostat prescribing information states use with drugs known to prolong QTc is not recommended.

• pantoprazole

  Monitor Closely (1)pantoprazole will decrease the level or effect of saquinavir by unknown mechanism. Use Caution/Monitor. Potential for increased toxicity.

• paricalcitol

  Monitor Closely (1)saquinavir increases levels of paricalcitol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• pasireotide

  Monitor Closely (1)saquinavir and pasireotide both increase QTc interval. Modify Therapy/Monitor Closely.

• pazopanib

  Serious - Use Alternative (1)saquinavir increases levels of pazopanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• pemigatinib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of pemigatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors is unavoidable, reduce pemigatinib dose (refer to drug monograph dosage modifications). After discontinuing the CYP3A4 inhibitor for 3 elimination half-lives, may resume previous pemigatinib dose.

• penbutolol

  Monitor Closely (1)saquinavir, penbutolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• pentamidine

  Serious - Use Alternative (1)saquinavir, pentamidine. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Increased risk of PR or QT prolongation and cardiac arrhythmias.

• pentobarbital

  Monitor Closely (1)pentobarbital will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• perampanel

  Monitor Closely (1)saquinavir will increase the level or effect of perampanel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• perphenazine

  Serious - Use Alternative (1)saquinavir, perphenazine. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Increased risk of PR or QT prolongation and cardiac arrhythmias.

• pexidartinib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of pexidartinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors is unavoidable, reduce pexidartinib dose (refer to drug monograph dosage modifications). After discontinuing the CYP3A4 inhibitor for 3 elimination half-lives, may resume previous pexidartinib dose.

• phenobarbital

  Monitor Closely (2)phenobarbital will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  phenobarbital will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• phenytoin

  Monitor Closely (2)phenytoin will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Clinicians may want to consider using alternative medication to phenytoin in patients on saquinavir therapy. However, if it becomes necessary to give these agents concurrently, upward adjustments in saquinavir dosing may be needed to maintain antiviral effectiveness.
  
  phenytoin will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• pimavanserin

  Serious - Use Alternative (1)saquinavir will increase the level or effect of pimavanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Decrease dose to 17 mg/day if pimavanserin is coadministered with strong CYP3A4 inhibitors.

• pimozide

  Serious - Use Alternative (2)saquinavir increases levels of pimozide by decreasing metabolism. Contraindicated. Risk of prolonged QTc interval.
  
  saquinavir will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• pindolol

  Monitor Closely (1)saquinavir, pindolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• pitavastatin

  Monitor Closely (1)saquinavir increases toxicity of pitavastatin by Other (see comment). Use Caution/Monitor. Comment: OATP1B1 inhibitors may increase risk of myopathy.

• pitolisant

  Serious - Use Alternative (2)saquinavir and pitolisant both increase QTc interval. Avoid or Use Alternate Drug.
  
  saquinavir will increase the level or effect of pitolisant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• polatuzumab vedotin

  Monitor Closely (1)saquinavir will increase the level or effect of polatuzumab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Polatuzumab undergoes catabolism to small peptides, amino acids, monomethyl auristatin E (MMAE), and unconjugated MMAE-related catabolites. MMAE is a CYP3A4 substrate. Coadministration of polatuzumab vedotin with a strong CYP3A4 inhibitor may increase unconjugated MMAE AUC, which may increase polatuzumab vedotin toxicities.

• pomalidomide

  Serious - Use Alternative (2)saquinavir increases levels of pomalidomide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  saquinavir increases levels of pomalidomide by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• ponatinib

  Monitor Closely (1)ponatinib increases levels of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir increases levels of ponatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Decrease ponatinib starting dose to 30 mg qDay if coadministration with strong CYP3A4 inhibitors cannot be avoided.

• posaconazole

  Monitor Closely (1)posaconazole will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• pralsetinib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of pralsetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• pramlintide

  Monitor Closely (1)saquinavir decreases effects of pramlintide by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• pravastatin

  Monitor Closely (1)saquinavir increases toxicity of pravastatin by Other (see comment). Use Caution/Monitor. Comment: OATP1B1 inhibitors may increase risk of myopathy.

• praziquantel

  Monitor Closely (1)saquinavir will increase the level or effect of praziquantel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• prednisone

  Monitor Closely (1)prednisone will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• primaquine

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

• primidone

  Monitor Closely (1)primidone will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• procainamide

  Serious - Use Alternative (1)saquinavir, procainamide. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Increased risk of PR or QT prolongation and cardiac arrhythmias.

• prochlorperazine

  Serious - Use Alternative (1)saquinavir, prochlorperazine. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.

• progesterone intravaginal gel

  Monitor Closely (1)saquinavir will increase the level or effect of progesterone intravaginal gel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• progesterone micronized

  Monitor Closely (1)saquinavir will increase the level or effect of progesterone micronized by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• progesterone, natural

  Monitor Closely (1)saquinavir will increase the level or effect of progesterone, natural by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• quazepam

  Serious - Use Alternative (1)saquinavir will increase the level or effect of quazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• quercetin

  Monitor Closely (1)quercetin will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• quetiapine

  Monitor Closely (2)saquinavir increases levels of quetiapine by QTc interval. Modify Therapy/Monitor Closely. Potential for increased toxicity. Use alternatives if available. Increased risk of QT prolongation and cardiac arrhythmias.
  
  quetiapine, saquinavir. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.Serious - Use Alternative (1)saquinavir will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• quinidine

  Contraindicated (1)saquinavir will increase the level or effect of quinidine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Serious - Use Alternative (1)quinidine will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• quinine

  Monitor Closely (1)saquinavir and quinine both increase QTc interval. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of quinine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• quinupristin/dalfopristin

  Monitor Closely (1)quinupristin/dalfopristin will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• rabeprazole

  Monitor Closely (1)rabeprazole will increase the level or effect of saquinavir by unknown mechanism. Use Caution/Monitor. Potential for increased toxicity.

• ranolazine

  Monitor Closely (1)ranolazine will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of ranolazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• red yeast rice

  Serious - Use Alternative (1)saquinavir will increase the level or effect of red yeast rice by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. May increase creatine kinase levels and increase risk of myopathy or rhabdomyolysis; red yeast rice contains monocolin K (reportedly identical to lovastatin)

• regorafenib

  Contraindicated (1)saquinavir, regorafenib. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inhibitors increase regorafenib levels and decrease exposure of the active metabolites M-2 and M-5.

• repaglinide

  Monitor Closely (1)saquinavir will increase the level or effect of repaglinide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ribociclib

  Contraindicated (1)ribociclib increases toxicity of saquinavir by QTc interval. Contraindicated.Serious - Use Alternative (2)ribociclib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
  
  saquinavir will increase the level or effect of ribociclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If a strong CYP3A inhibitor must be coadministered with ribociclib, reduce the ribociclib starting dose to 400 mg/day.

• rifabutin

  Monitor Closely (1)rifabutin decreases levels of saquinavir by increasing metabolism. Use Caution/Monitor. If saquinavir administered with ritonavir as boosted therapy, interaction not clinically significant.Serious - Use Alternative (2)rifabutin will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  saquinavir will decrease the level or effect of rifabutin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Dosage reduction of rifabutin by at least 75% of the usual dose of 300 mg/day is recommended (ie, a maximum dose of 150 mg every other day or 3 times/week). Increased monitoring for adverse events is warranted in patients receiving the combination. Consider monitoring rifabutin concentrations to ensure adequate exposure.

• rifampin

  Contraindicated (2)rifampin will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Contraindicated. May result in loss of antiviral efficacy and/or development of viral resistance.
  
  rifampin increases toxicity of saquinavir by unspecified interaction mechanism. Contraindicated. Adding rifampin to saquinavir/ritonaivr (ritonavir boosted saquinavir) may result in toxic hepatitis.

• rifapentine

  Monitor Closely (1)rifapentine will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)rifapentine decreases levels of saquinavir by increasing metabolism. Contraindicated.

• rifaximin

  Monitor Closely (1)saquinavir increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• rilpivirine

  Monitor Closely (2)saquinavir increases levels of rilpivirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Rilpivirine is not expected to affect the plasma concentrations of co-administered protease inhibitors. .
  
  rilpivirine increases toxicity of saquinavir by QTc interval. Use Caution/Monitor. Rilpivirine should be used with caution when co-administered with a drug with a known risk of Torsade de Pointes.

• rimegepant

  Serious - Use Alternative (2)saquinavir will increase the level or effect of rimegepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  saquinavir will increase the level or effect of rimegepant by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

• riociguat

  Serious - Use Alternative (3)saquinavir will increase the level or effect of riociguat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  saquinavir will increase the level or effect of riociguat by decreasing metabolism. Avoid or Use Alternate Drug. Coadministration of riociguat (substrate of CYP isoenzymes 1A1, 2C8, 3A, 2J2) with strong CYP inhibitors may require a decreased initial dose of 0.5 mg PO TID; monitor for signs of hypotension and reduce dose if needed
  
  saquinavir will increase the level or effect of riociguat by Other (see comment). Avoid or Use Alternate Drug. Coadministration of riociguat (an ABCG2 [BCRP] substrate) with strong ABCG2 inhibitors may require a decreased initial dose of 0.5 mg PO TID; monitor for signs of hypotension and reduce dose if needed

• ripretinib

  Monitor Closely (1)saquinavir will increase the level or effect of ripretinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration with a strong CYP3A inhibitor will increase systemic exposure to ripretinib and its active metabolite (DP-5439), which may increase risk of adverse reactions.

• ritonavir

  Monitor Closely (3)ritonavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Saquinavir is intended to be administered with ritonavir (boosted therapy). The combination has shown to cause dose-dependent QT and PR interval prolongation. Caution in treatment naïve patients. Reduce starting dose and perform an on-treatment ECG after approximately 10 days.
  
  ritonavir will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
  
  ritonavir and saquinavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of ritonavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rivaroxaban

  Monitor Closely (1)saquinavir increases levels of rivaroxaban by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Avoid concomitant use of rivaroxaban and combined Pgp and strong CYP3A4 inhibitors. Combination may lead to significant increases in rivaroxaban levels and increase bleeding risk.

• romidepsin

  Serious - Use Alternative (1)saquinavir will increase the level or effect of romidepsin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with strong 3A4 inhibitors shoul d be avoided if possible.

• rosiglitazone

  Monitor Closely (1)saquinavir decreases effects of rosiglitazone by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• rosuvastatin

  Serious - Use Alternative (1)saquinavir increases toxicity of rosuvastatin by Other (see comment). Avoid or Use Alternate Drug. Comment: OATP1B1 inhibitors may increase risk of myopathy.

• rucaparib

  Monitor Closely (1)rucaparib will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.

• rufinamide

  Monitor Closely (1)rufinamide will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ruxolitinib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Reduce ruxolitinib starting dose to 10 mg BID with platelet count 100 X 10^9/L or more and concurrent use of strong CYP3A4 inhibitors; avoid with platelet counts <100 X 10^9/L

• ruxolitinib topical

  Serious - Use Alternative (1)saquinavir will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Reduce ruxolitinib starting dose to 10 mg BID with platelet count 100 X 10^9/L or more and concurrent use of strong CYP3A4 inhibitors; avoid with platelet counts <100 X 10^9/L

• sacubitril/valsartan

  Monitor Closely (1)saquinavir will increase the level or effect of sacubitril/valsartan by Other (see comment). Use Caution/Monitor. The results from an in vitro study with human liver tissue indicate that valsartan is a substrate of the hepatic uptake transporter OATP1B1; coadministration with OATP1B1 inhibitors may increase valsartan systemic exposure

• salmeterol

  Monitor Closely (1)saquinavir increases levels of salmeterol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• sarecycline

  Monitor Closely (1)sarecycline will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor for toxicities of P-gp substrates that may require dosage reduction when coadministered with P-gp inhibitors.

• saxagliptin

  Monitor Closely (1)saquinavir will increase the level or effect of saxagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Limit saxagliptin dose to 2.5 mg/day when coadministered with strong CYP3A4 inhibitors

• secobarbital

  Monitor Closely (1)secobarbital will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• selpercatinib

  Monitor Closely (1)selpercatinib increases toxicity of saquinavir by QTc interval. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of selpercatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• selumetinib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of selumetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with strong or moderate CYP3A4 inhibitors cannot be avoided, reduce selumetinib dosage (refer to selumetinib monograph for further information). After discontinuation of the strong or moderate CYP3A4 inhibitor for 3 elimination half-lives, resume selumetinib dose that was taken before initiating the inhibitor.

• sertraline

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

• sevoflurane

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

• sildenafil

  Monitor Closely (1)saquinavir increases levels of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. Increased risk of priapism, hypotension, and other adverse effects.

• silodosin

  Monitor Closely (1)saquinavir increases levels of silodosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Potential for increased toxicity. Use alternatives if available.

• simvastatin

  Contraindicated (3)simvastatin will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Contraindicated.
  
  saquinavir increases levels of simvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Contraindicated. Increased risk for rhabdomyolysis with drugs that increase simvastatin systemic exposure.
  
  saquinavir increases toxicity of simvastatin by Other (see comment). Contraindicated. Comment: OATP1B1 inhibitors may increase risk of myopathy.

• siponimod

  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.

• sirolimus

  Monitor Closely (1)sirolimus will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of sirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• sitagliptin

  Monitor Closely (1)saquinavir decreases effects of sitagliptin by Other (see comment). Use Caution/Monitor. Comment: Reports of hyperglycemia due to insulin resistance with protease inhibitors. .

• sofosbuvir/velpatasvir

  Monitor Closely (1)saquinavir will increase the level or effect of sofosbuvir/velpatasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• solifenacin

  Serious - Use Alternative (2)saquinavir increases levels of solifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of PR or QT prolongation and cardiac arrhythmias.
  
  solifenacin and saquinavir both increase QTc interval. Avoid or Use Alternate Drug.

• sonidegib

  Serious - Use Alternative (1)saquinavir will increase the level or effect of sonidegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sonidegib with strong CYP3A4 inhibitors.

• sorafenib

  Contraindicated (1)saquinavir will increase the level or effect of sorafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Monitor Closely (1)sorafenib and saquinavir both increase QTc interval. Use Caution/Monitor.

• sotalol

  Serious - Use Alternative (1)saquinavir, sotalol. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of QT prolongation and cardiac arrhythmias.

• sotorasib

  Serious - Use Alternative (1)sotorasib will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If use is unavoidable, refer to the prescribing information of the P-gp substrate for dosage modifications.

• St John's Wort

  Contraindicated (1)St John's Wort will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Monitor Closely (1)St John's Wort will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)St John's Wort decreases levels of saquinavir by increasing metabolism. Contraindicated.

• stavudine

  Monitor Closely (1)saquinavir and stavudine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• stiripentol

  Monitor Closely (3)stiripentol, saquinavir. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.
  
  stiripentol will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Consider reducing the dose of P-glycoprotein (P-gp) substrates, if adverse reactions are experienced when administered concomitantly with stiripentol.
  
  saquinavir will increase the level or effect of stiripentol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• sufentanil

  Monitor Closely (1)saquinavir will increase the level or effect of sufentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• sufentanil SL

  Monitor Closely (1)saquinavir will increase the level or effect of sufentanil SL by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of sufentanil SL with any CYP3A4 inhibitor may increase sufentanil plasma concentration, and, thereby increase or prolonged adverse effects, including potentially fatal respiratory depression.

• sunitinib

  Contraindicated (1)sunitinib and saquinavir both increase QTc interval. Contraindicated.Serious - Use Alternative (1)saquinavir increases levels of sunitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. Increased risk of QT prolongation and cardiac arrhythmias.

• suvorexant

  Serious - Use Alternative (1)saquinavir increases levels of suvorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Suvorexant not recommended with use of strong CYP3A4 inhibitors.

• tacrolimus

  Contraindicated (2)saquinavir will increase the level or effect of tacrolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
  
  tacrolimus and saquinavir both increase QTc interval. Contraindicated.Monitor Closely (1)tacrolimus will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• tacrolimus ointment

  Monitor Closely (1)saquinavir will increase the level or effect of tacrolimus ointment by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tadalafil

  Monitor Closely (1)saquinavir increases levels of tadalafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .

• tamoxifen

  Monitor Closely (1)saquinavir, tamoxifen. Either increases effects of the other by QTc interval. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir, tamoxifen. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. CYP3A4 inhibition decreases metabolism of tamoxifen to N-desmethyl tamoxifen (active metabolite with similar biologic activity).

• tamsulosin

  Serious - Use Alternative (1)saquinavir increases levels of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• tasimelteon

  Monitor Closely (1)saquinavir will increase the level or effect of tasimelteon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tazemetostat

  Monitor Closely (1)tazemetostat will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• tecovirimat

  Monitor Closely (1)tecovirimat will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.

• telavancin

  Serious - Use Alternative (1)saquinavir, telavancin. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug.

• temsirolimus

  Serious - Use Alternative (1)saquinavir will increase the level or effect of temsirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• teniposide

  Monitor Closely (1)saquinavir will increase the level or effect of teniposide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

• tenofovir DF

  Monitor Closely (1)saquinavir and tenofovir DF both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• tepotinib

  Serious - Use Alternative (2)saquinavir will increase the level or effect of tepotinib by Other (see comment). Avoid or Use Alternate Drug. Interaction not studied clinically. Metabolism and data suggest drugs that are strong CYP3A4 and P-gp inhibitors may increase tepotinib (a P-gp and CYP3A4 substrate) effects and risk of toxicities.
  
  tepotinib will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If concomitant use unavoidable, reduce the P-gp substrate dosage if recommended in its approved product labeling.

• terbinafine

  Monitor Closely (1)saquinavir will increase the level or effect of terbinafine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tezacaftor

  Monitor Closely (1)saquinavir will increase the level or effect of tezacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust tezacaftor dosage regimen if coadministered with a strong CYP3A inhibitor.

• thioridazine

  Monitor Closely (1)saquinavir, thioridazine. Either increases toxicity of the other by QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available.

• tiagabine

  Serious - Use Alternative (1)saquinavir will increase the level or effect of tiagabine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ticagrelor

  Monitor Closely (1)saquinavir increases levels of ticagrelor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Ticagrelor is metabolized by CYP3A4/5. Avoid use with strong CYP3A inhibitors.

• timolol

  Monitor Closely (1)saquinavir, timolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• tinidazole

  Monitor Closely (1)saquinavir will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tipranavir

  Contraindicated (2)saquinavir will increase the level or effect of tipranavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
  
  tipranavir will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Monitor Closely (1)saquinavir and tipranavir both increase risk of immune reconstitution syndrome. Use Caution/Monitor.Serious - Use Alternative (1)tipranavir decreases levels of saquinavir by unspecified interaction mechanism. Avoid or Use Alternate Drug.

• tisotumab vedotin

  Monitor Closely (1)saquinavir increases levels of tisotumab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tisotumab vedotin?s active metabolite (MMAE) is a CYP3A4 substrate. Coadministration with strong CYP3A4 inhibitors may increase unconjugated MMAE systemic exposure and increase risk of adverse effects.

• tofacitinib

  Serious - Use Alternative (1)saquinavir increases levels of tofacitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Reduce tofacitinib dose to 5 mg qDay when coadministered with potent CYP3A4 inhibitors.

• tolterodine

  Serious - Use Alternative (1)saquinavir will increase the level or effect of tolterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• tolvaptan

  Monitor Closely (1)tolvaptan will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of tolvaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• topiramate

  Monitor Closely (1)topiramate will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• topotecan

  Serious - Use Alternative (1)saquinavir will increase the level or effect of topotecan by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. Product labeling for PO topotecan recommends avoiding concomitant use of P-gp inhibitors; the interaction with IV topotecan may be less severe but is still likely of clinical significance

• toremifene

  Monitor Closely (1)saquinavir increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

• trabectedin

  Serious - Use Alternative (1)saquinavir will increase the level or effect of trabectedin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If strong CYP3A inhibitor must be used, short-term (eg, less than 14 days), administer strong CYP3A inhibitor 1 week after trabectedin infusion, and discontinue the day prior to next trabectedin infusion

• tramadol

  Monitor Closely (1)saquinavir will increase the level or effect of tramadol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• trazodone

  Contraindicated (2)trazodone will decrease the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Contraindicated.
  
  saquinavir will increase the level or effect of trazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

• triamcinolone acetonide injectable suspension

  Monitor Closely (1)saquinavir will increase the level or effect of triamcinolone acetonide injectable suspension by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• triazolam

  Contraindicated (1)saquinavir will increase the level or effect of triazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Serious - Use Alternative (1)saquinavir increases levels of triazolam by decreasing metabolism. Contraindicated.

• triclabendazole

  Monitor Closely (1)triclabendazole and saquinavir both increase QTc interval. Use Caution/Monitor.

• trimipramine

  Monitor Closely (1)saquinavir will increase the level or effect of trimipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• triptorelin

  Monitor Closely (1)triptorelin increases toxicity of saquinavir by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• tucatinib

  Monitor Closely (1)tucatinib will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Consider reducing the dosage of P-gp substrates, where minimal concentration changes may lead to serious or life-threatening toxicities.Serious - Use Alternative (1)tucatinib will increase the level or effect of saquinavir 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.

• ubrogepant

  Serious - Use Alternative (1)saquinavir will increase the level or effect of ubrogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ulipristal

  Monitor Closely (1)saquinavir will increase the level or effect of ulipristal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• umeclidinium bromide/vilanterol inhaled

  Monitor Closely (1)saquinavir will increase the level or effect of umeclidinium bromide/vilanterol inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Vilanterol is a CYP3A4 substrate; coadministration with potent CYP3A4 inhibitors may increase systemic exposureSerious - Use Alternative (1)saquinavir increases toxicity of umeclidinium bromide/vilanterol inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

• upadacitinib

  Monitor Closely (1)saquinavir will increase the level or effect of upadacitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Caution if upadacitinib is coadministered with strong CYP3A4 inhibitors.

• valbenazine

  Monitor Closely (1)saquinavir will increase the level or effect of valbenazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce valbenazine dose to 40 mg once daily when coadministered with a strong CYP3A4 inhibitor.

• valsartan

  Monitor Closely (1)saquinavir will increase the level or effect of valsartan by Other (see comment). Use Caution/Monitor. The results from an in vitro study with human liver tissue indicate that valsartan is a substrate of the hepatic uptake transporter OATP1B1; coadministration with OATP1B1 inhibitors may increase valsartan systemic exposure

• vandetanib

  Serious - Use Alternative (2)saquinavir, vandetanib. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Avoid coadministration with drugs known to prolong QT interval; if a drug known to prolong QT interval must be used, more frequent ECG monitoring is recommended.
  
  saquinavir will increase the level or effect of vandetanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• vardenafil

  Serious - Use Alternative (1)saquinavir increases levels of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for increased toxicity. .

• velpatasvir

  Monitor Closely (1)saquinavir will increase the level or effect of velpatasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• vemurafenib

  Contraindicated (1)saquinavir will increase the level or effect of vemurafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Serious - Use Alternative (1)vemurafenib and saquinavir both increase QTc interval. Avoid or Use Alternate Drug. Concomitant use of vemurafenib with drugs that prolong QT interval is not recommended. Saquinavir may also increase levels of vemurafenib.

• venetoclax

  Contraindicated (1)saquinavir will increase the level or effect of venetoclax by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Use of strong CYP3A4 inhibitors is contraindicated with venetoclax during the initial ramp-up dosing phase. If a strong CYP3A inhibitor must be used after the ramp-up phase, reduce the venetoclax dose by at least 75%.

• venlafaxine

  Serious - Use Alternative (1)saquinavir, venlafaxine. Either increases toxicity of the other by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. May increase risk for QT prolongation.

• verapamil

  Monitor Closely (2)verapamil will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)saquinavir will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• vilanterol/fluticasone furoate inhaled

  Monitor Closely (1)saquinavir will increase the level or effect of vilanterol/fluticasone furoate inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Fluticasone furoate and vilanterol are both CYP3A4 substrates; coadministration with potent CYP3A4 inhibitors may increase systemic exposureSerious - Use Alternative (1)saquinavir increases toxicity of vilanterol/fluticasone furoate inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

• vilazodone

  Serious - Use Alternative (1)saquinavir increases levels of vilazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If intolerable adverse effects occur when coadministered with moderate CYP3A4 inhibitors, reduce daily dose to 20 mg.

• vinblastine

  Monitor Closely (1)saquinavir will increase the level or effect of vinblastine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• vincristine

  Serious - Use Alternative (1)saquinavir will increase the level or effect of vincristine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• vincristine liposomal

  Serious - Use Alternative (1)saquinavir will increase the level or effect of vincristine liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• vinorelbine

  Monitor Closely (1)saquinavir will increase the level or effect of vinorelbine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• voclosporin

  Contraindicated (1)saquinavir will increase the level or effect of voclosporin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.Monitor Closely (1)voclosporin, saquinavir. Either increases effects of the other by QTc interval. Use Caution/Monitor.

• vorapaxar

  Serious - Use Alternative (1)saquinavir increases levels of vorapaxar by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• voriconazole

  Serious - Use Alternative (2)saquinavir will increase the level or effect of voriconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
  
  voriconazole will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• vorinostat

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

• voxelotor

  Serious - Use Alternative (1)voxelotor will increase the level or effect of saquinavir 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.

• voxilaprevir

  Monitor Closely (1)saquinavir will increase the level or effect of voxilaprevir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• warfarin

  Monitor Closely (1)saquinavir will increase the level or effect of warfarin by Other (see comment). Use Caution/Monitor. Warfarin's less potent R-enantiomer is metabolized in part by CYP3A4 (and also CYP1A2 and CYP2C19). Monitor INR more frequently if coadministered with inhibitors of these isoenzymes and adjust warfarin dose if needed.

• zafirlukast

  Monitor Closely (1)zafirlukast will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• zanubrutinib

  Monitor Closely (1)saquinavir will increase the level or effect of zanubrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce zanubrutinib dose when coadministered with a strong CYP3A4 inhibitor. Interrupt dose as recommended for adverse reactions. After discontinuing the CYP3A4 inhibitor, resume previous dose of zanubrutinib. See zanubrutinib Dosage Modifications for precise recommendation.

• zidovudine

  Monitor Closely (1)saquinavir and zidovudine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.

• ziprasidone

  Contraindicated (1)ziprasidone increases toxicity of saquinavir by QTc interval. Contraindicated. Potential for serious and/or life threatening reactions such as cardiac arrhythmias.

• zolpidem

  Monitor Closely (1)saquinavir will increase the level or effect of zolpidem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• zonisamide

  Monitor Closely (1)saquinavir will increase the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.