fedratinib (Rx)

Myelofibrosis

Indicated for adults with intermediate-2 or high-risk primary or secondary (post-polycythemia vera or post-essential thrombocythemia) myelofibrosis (MF)

Baseline platelet count ≥50 x 10⁹/L: 400 mg PO qDay

Dosage Modifications

Discontinue treatment if unable to tolerate 200 mg qDay

Coadministration of strong CYP3A4 inhibitors

• Reduce fedratinib dose to 200 mg qDay
• If strong CYP3A4 inhibitor is discontinued, increase fedratinib dose to 300 mg qDay during the first 2 weeks after discontinuing the CYP3A4 inhibitor, and then to 400 mg qDay thereafter as tolerated

Dual CYP3A4 and CYP2C19 inhibitors

• Requires more intensive safety monitoring and, if necessary, dose modifications based on adverse reactions

Hematologic adverse reactions

• Grade 4 thrombocytopenia, Grade 3 thrombocytopenia with bleeding, or Grade 4 neutropenia

  • Interrupt dose until resolved to Grade ≤2 or baseline
  • Restart at 100 mg qDay below the last given dose
  • Consider dose reduction in patients who become transfusion-dependent during treatment

Nausea, vomiting, diarrhea

• Grade ≥3 nausea, vomiting, diarrhea nonresponsive to supportive measure after 48 hr: Interrupt dose until resolved to Grade ≤1 or baseline
• Restart at 100 mg qDay below the last given dose

Hepatoxicity

• Grade ≥3 ALT, AST, bilirubin: Interrupt dose until resolved to Grade ≤1 or baseline
• Restart at 100 mg qDay below the last given dose
• Closely monitor ALT, AST, and bilirubin after dose reduction
• If Grade ≥3 recurs, discontinue treatment

Other nonhematologic toxicities

• Grade ≥3: Interrupt dose until resolved to Grade ≤2 or baseline
• Restart at 100 mg qDay below the last given dose

Renal impairment

• Mild-to-moderate (CrCl 30 to <90 mL/min): No dosage adjustment necessary; patients with preexisting moderate renal impairment require close monitoring and dosage modifications based on adverse reactions if necessary
• Severe (CrCl 15 to <30 mL/min): Reduce to 200 mg qDay

Hepatic impairment

• Mild-to-moderate (total bilirubin ≤3x ULN and any AST): No dosage adjustment necessary
• Severe (total bilirubin >3x ULN and any AST): Avoid use; pharmacokinetics not evaluated

Dosing Considerations

Patients treated with ruxolitinib before initiating fedratinib must taper and discontinue according to the ruxolitinib prescribing information

Monitor parameters

• Monitor the following before starting treatment, periodically during treatment, and as clinically indicated

  • Thiamine (vitamin B-1) level
  • Complete blood cell count
  • Creatinine and BUN
  • Hepatic panel
  • Amylase and lipase

Management of thiamine levels and Wernicke encephalopathy

• Assess thiamine levels and nutritional status before starting treatment, periodically during treatment, and as clinically indicated
• Do not start in patients with thiamine deficiency; replete thiamine before initiating and during treatment if thiamine levels are low
• If Wernicke encephalopathy is suspected, immediately discontinue treatment and initiate parenteral thiamine treatment
• Monitor until symptoms resolve or improve and thiamine levels normalize

Safety and efficacy not established

Contraindicated (2)

• lonafarnib

  fedratinib 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.

• mavacamten

  fedratinib will increase the level or effect of mavacamten by affecting hepatic enzyme CYP2C19 metabolism. Contraindicated. Strong or moderate CYP2C19 inhibitors may increase mavacamten systemic exposure, resulting in heart failure due to systolic dysfunction.

Serious - Use Alternative (117)

• amiodarone

  amiodarone 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.

• amobarbital

  amobarbital will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• apalutamide

  apalutamide will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• apomorphine

  apomorphine 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.

• aprepitant

  aprepitant 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.

• armodafinil

  armodafinil will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a moderate CYP3A4 inducer with fedratinib has not been studied.

• atazanavir

  atazanavir 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.

• avapritinib

  fedratinib 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 moderate CYP3A4 inhibitors. If unable to avoid, reduce avapritinib starting dose. See drug monograph Dosage Modifications.

• azelastine

  azelastine 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.

• bexarotene

  bexarotene will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a moderate CYP3A4 inducer with fedratinib has not been studied.

• bortezomib

  bortezomib 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.

• bosentan

  bosentan will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• brigatinib

  brigatinib will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a moderate CYP3A4 inducer with fedratinib has not been studied.

• butabarbital

  butabarbital will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• butalbital

  butalbital will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• carbamazepine

  carbamazepine will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• ceritinib

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

• chloramphenicol

  chloramphenicol 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.
  
  chloramphenicol 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.

• cimetidine

  cimetidine 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.

• clarithromycin

  clarithromycin 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.

• clobazam

  clobazam will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a moderate CYP3A4 inducer with fedratinib has not been studied.

• clozapine

  clozapine 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.

• cobicistat

  cobicistat 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.

• conivaptan

  conivaptan 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.

• dabrafenib

  dabrafenib will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• darunavir

  darunavir 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.

• dexlansoprazole

  dexlansoprazole 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.

• diazepam

  diazepam 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.

• drospirenone

  drospirenone 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.

• efavirenz

  efavirenz will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• elacestrant

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

• encorafenib

  encorafenib will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a moderate CYP3A4 inducer with fedratinib has not been studied.

• enzalutamide

  enzalutamide will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• eslicarbazepine acetate

  eslicarbazepine acetate will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a moderate CYP3A4 inducer with fedratinib has not been studied.

• ethinylestradiol

  ethinylestradiol 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.

• etrasimod

  etrasimod, fedratinib. Either increases effects of the other by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Risk of additive immune system effects with etrasimod has not been studied in combination with antineoplastic, immune-modulating, or noncorticosteroid immunosuppressive therapies. Avoid coadministration during and in the weeks following administration of etrasimod.

• etravirine

  etravirine will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• felodipine

  felodipine 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.

• fexinidazole

  fexinidazole will increase the level or effect of fedratinib 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.

• fluconazole

  fluconazole 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.

• fluoxetine

  fluoxetine 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.

• fluvoxamine

  fluvoxamine 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 coadminitration of a dual CYP3A4 and CYP2C19 inhibitor with fedratinib not studied

• fosaprepitant

  fosaprepitant 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.

• fosphenytoin

  fosphenytoin will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• grapefruit

  grapefruit 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.

• idelalisib

  idelalisib 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.

• imatinib

  imatinib 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.

• indinavir

  indinavir 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.
  
  indinavir 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.

• infigratinib

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

• isoniazid

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

• itraconazole

  itraconazole 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.

• ivosidenib

  ivosidenib will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• ketoconazole

  ketoconazole 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.
  
  ketoconazole 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.

• lansoprazole

  lansoprazole 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.

• larotrectinib

  larotrectinib 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.

• lemborexant

  fedratinib 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

  lenvatinib 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.

• levoketoconazole

  levoketoconazole 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.
  
  levoketoconazole 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.

• lopinavir

  lopinavir 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.

• lorlatinib

  lorlatinib will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• losartan

  losartan 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.

• lumacaftor/ivacaftor

  lumacaftor/ivacaftor will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• lurbinectedin

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

• mestranol

  mestranol 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.

• methimazole

  methimazole 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.

• methoxsalen

  methoxsalen 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.

• mifepristone

  mifepristone 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.

• mitotane

  mitotane will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• mobocertinib

  fedratinib will increase the level or effect of mobocertinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If use of moderate CYP3A4 inhibitor unavoidable, reduce mobocertinib dose by ~50% (eg, 160 to 80 mg); closely monitor QTc interval.

• modafinil

  modafinil 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.

• nafcillin

  nafcillin will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• nefazodone

  nefazodone 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.

• nelfinavir

  nelfinavir 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.
  
  nelfinavir 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.

• nicardipine

  nicardipine 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.

• nirogacestat

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

• olanzapine

  olanzapine 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.

• omaveloxolone

  fedratinib will increase the level or effect of omaveloxolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unavoidable, reduce omaveloxolone dose to 100 mg/day. Closely monitor for adverse effects. If adverse effects emerge, further reduce to 50 mg/day.

• omeprazole

  omeprazole 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.

• orphenadrine

  orphenadrine 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.

• pacritinib

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

• paroxetine

  paroxetine 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.

• pemigatinib

  fedratinib 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

  pentamidine 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.

• pentobarbital

  pentobarbital will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• pexidartinib

  fedratinib 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

  phenobarbital will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• phenytoin

  phenytoin will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• pimozide

  pimozide 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.

• posaconazole

  posaconazole 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.

• primidone

  primidone will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• progesterone intravaginal gel

  progesterone intravaginal gel 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.

• progesterone micronized

  progesterone micronized 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.

• progesterone, natural

  progesterone, natural 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.

• propofol

  propofol 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.

• rabeprazole

  rabeprazole 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.

• repotrectinib

  fedratinib will increase the level or effect of repotrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Discontinue strong or moderate CYP3A inhibitors and wait 3-5 elimination half-lives before initiating repotrectinib.

• rifabutin

  rifabutin will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• rifampin

  rifampin will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• rifapentine

  rifapentine will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• ritonavir

  ritonavir 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.
  
  ritonavir 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.

• saquinavir

  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.

• secobarbital

  secobarbital will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• selegiline

  selegiline 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.

• selegiline transdermal

  selegiline transdermal 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.

• selumetinib

  fedratinib 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 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.

• St John's Wort

  St John's Wort will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• stiripentol

  stiripentol 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.

• tazemetostat

  fedratinib will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of tazemetostat with moderate CYP3A4 inhibitors. If coadministration is unavoidable, reduce tazemetostat current dose (see drug monograph Dosage Modifications).

• telotristat ethyl

  telotristat ethyl will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a moderate CYP3A4 inducer with fedratinib has not been studied.

• tipranavir

  tipranavir 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.

• tranylcypromine

  tranylcypromine 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.

• tucatinib

  tucatinib will increase the level or effect of fedratinib 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.

• valproic acid

  valproic acid 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.

• voriconazole

  voriconazole 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.
  
  voriconazole 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.

• voxelotor

  voxelotor will increase the level or effect of fedratinib 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.

• zafirlukast

  zafirlukast 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.

Monitor Closely (359)

• abemaciclib

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

• acalabrutinib

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

• ado-trastuzumab emtansine

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

• alfentanil

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

• alfuzosin

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

• alpelisib

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

• alprazolam

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

• ambrisentan

  fedratinib will increase the level or effect of ambrisentan by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• amiodarone

  fedratinib will increase the level or effect of amiodarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of amiodarone by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• amitriptyline

  fedratinib will increase the level or effect of amitriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• amlodipine

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

• amoxapine

  fedratinib will increase the level or effect of amoxapine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• apalutamide

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

• apixaban

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

• apremilast

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

• aprepitant

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

• aripiprazole

  fedratinib will increase the level or effect of aripiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of aripiprazole by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• armodafinil

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

• atazanavir

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

• atogepant

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

• atomoxetine

  fedratinib will increase the level or effect of atomoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• atorvastatin

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

• avanafil

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

• axitinib

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

• bedaquiline

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

• belzutifan

  belzutifan will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If unable to avoid coadministration of belzutifan with sensitive CYP3A4 substrates, consider increasing the sensitive CYP3A4 substrate dose in accordance with its prescribing information.

• benzhydrocodone/acetaminophen

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

• benzphetamine

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

• bortezomib

  fedratinib will increase the level or effect of bortezomib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of bortezomib by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• bosentan

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

• bosutinib

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

• brentuximab vedotin

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

• brexpiprazole

  fedratinib will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• brigatinib

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

• bromocriptine

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

• budesonide

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

• buprenorphine

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

• buprenorphine subdermal implant

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

• buprenorphine transdermal

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

• buspirone

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

• busulfan

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

• cabozantinib

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

• calcifediol

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

• calcitriol

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

• capivasertib

  fedratinib will increase the level or effect of capivasertib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce capivasertib dose if coadministered with moderate CYP3A inhibitors.

• captopril

  fedratinib will increase the level or effect of captopril by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• carbamazepine

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

• cariprazine

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

• carisoprodol

  fedratinib will increase the level or effect of carisoprodol by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• carvedilol

  fedratinib will increase the level or effect of carvedilol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• cenobamate

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

• ceritinib

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

• chlordiazepoxide

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

• chloroquine

  fedratinib will increase the level or effect of chloroquine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of chloroquine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• chlorpheniramine

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

• chlorpromazine

  fedratinib will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• ciclesonide inhaled

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

• ciclesonide intranasal

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

• cilostazol

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

• cinacalcet

  fedratinib will increase the level or effect of cinacalcet by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• citalopram

  fedratinib will increase the level or effect of citalopram by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.
  
  fedratinib will increase the level or effect of citalopram by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• clarithromycin

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

• clobazam

  fedratinib will increase the level or effect of clobazam by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• clomipramine

  fedratinib will increase the level or effect of clomipramine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.
  
  fedratinib will increase the level or effect of clomipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• clorazepate

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

• cobicistat

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

• cobimetinib

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

• cocaine topical

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

• codeine

  fedratinib will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• colchicine

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

• conivaptan

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

• conjugated estrogens

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

• copanlisib

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

• crizotinib

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

• cyclophosphamide

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

• cyclosporine

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

• dabrafenib

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

• dantrolene

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

• dapsone

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

• daridorexant

  fedratinib will increase the level or effect of daridorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Daridorexant dose should not exceed 25 mg per night when coadministered with moderate CYP3A4 inhibitors.

• darifenacin

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

• darolutamide

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

• darunavir

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

• dasatinib

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

• deflazacort

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

• desipramine

  fedratinib will increase the level or effect of desipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• deutetrabenazine

  fedratinib will increase the level or effect of deutetrabenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• dexamethasone

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

• dexlansoprazole

  fedratinib will increase the level or effect of dexlansoprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of dexlansoprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• diazepam

  fedratinib will increase the level or effect of diazepam by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• diazepam intranasal

  fedratinib will increase the level or effect of diazepam intranasal by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Strong or moderate CYP2C19 inhibitors may decrease rate of diazepam elimination, thereby increasing adverse reactions to diazepam.
  
  fedratinib 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.

• dihydroergotamine

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

• dihydroergotamine inhaled

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

• diltiazem

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

• disopyramide

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

• docetaxel

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

• doravirine

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

• doxepin

  fedratinib will increase the level or effect of doxepin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• doxepin cream

  fedratinib will increase the level or effect of doxepin cream by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• doxorubicin

  fedratinib will increase the level or effect of doxorubicin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of doxorubicin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• doxorubicin liposomal

  fedratinib will increase the level or effect of doxorubicin liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of doxorubicin liposomal by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• dronabinol

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

• dronedarone

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

• duloxetine

  fedratinib will increase the level or effect of duloxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• duvelisib

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

• efavirenz

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

• elagolix

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

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

• eletriptan

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

• eliglustat

  fedratinib will increase the level or effect of eliglustat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of eliglustat by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• encorafenib

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

• entrectinib

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

• enzalutamide

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

• eplerenone

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

• ergoloid mesylates

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

• ergotamine

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

• erlotinib

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

• erythromycin base

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

• erythromycin ethylsuccinate

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

• erythromycin lactobionate

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

• erythromycin stearate

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

• escitalopram

  fedratinib will increase the level or effect of escitalopram by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of escitalopram by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• esomeprazole

  fedratinib will increase the level or effect of esomeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of esomeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• estradiol

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

• estrogens conjugated synthetic

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

• estrogens esterified

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

• estropipate

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

• eszopiclone

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

• ethinylestradiol

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

• etoposide

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

• etravirine

  fedratinib will increase the level or effect of etravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of etravirine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• everolimus

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

• exemestane

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

• felbamate

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

• fenofibrate

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

• fenofibrate micronized

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

• fenofibric acid

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

• fentanyl

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

• fentanyl intranasal

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

• fentanyl transdermal

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

• fentanyl transmucosal

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

• finerenone

  fedratinib will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or moderate CYP3A4 inhibitors. Adjust finererone dosage as needed.

• flecainide

  fedratinib will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• flibanserin

  fedratinib will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of flibanserin by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• flunisolide intranasal

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

• fluoxetine

  fedratinib will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• fluphenazine

  fedratinib will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• flurazepam

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

• flutamide

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

• fluticasone furoate

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

• fluticasone inhaled

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

• fluticasone intranasal

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

• fluvoxamine

  fedratinib will increase the level or effect of fluvoxamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of CYP2D6 substrates as necessary

• fosamprenavir

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

• fosaprepitant

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

• fosphenytoin

  fedratinib will increase the level or effect of fosphenytoin by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• fostamatinib

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

• gefitinib

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

• gepirone

  fedratinib will increase the level or effect of gepirone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce gepirone dose by 50% when used concomitantly with a moderate CYP3A4 inhibitor.

• glasdegib

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

• glecaprevir/pibrentasvir

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

• guanfacine

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

• haloperidol

  fedratinib will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• hydrocodone

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

• hydroxyprogesterone caproate (DSC)

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

• ibrutinib

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

• idelalisib

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

• ifosfamide

  fedratinib will increase the level or effect of ifosfamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of ifosfamide by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• iloperidone

  fedratinib will increase the level or effect of iloperidone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• imatinib

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

• imipramine

  fedratinib will increase the level or effect of imipramine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.
  
  fedratinib will increase the level or effect of imipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• indinavir

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

• irinotecan

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

• irinotecan liposomal

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

• isavuconazonium sulfate

  fedratinib will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• isosorbide dinitrate

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

• isosorbide mononitrate

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

• isradipine

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

• istradefylline

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

• itraconazole

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

• ivacaftor

  fedratinib 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 moderate CYP3A4 inhibitors. See specific ivacaftor-containing product for precise dosage modification.

• ivosidenib

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

• ixabepilone

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

• ixazomib

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

• ketamine

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

• lacosamide

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

• lansoprazole

  fedratinib will increase the level or effect of lansoprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of lansoprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• lapatinib

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

• larotrectinib

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

• lefamulin

  fedratinib will increase the level or effect of lefamulin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor for adverse effects if lefamulin is coadministered with moderate CYP3A inhibitors.

• lenacapavir

  lenacapavir will increase the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir (a moderate CYP3A4 inhibitor) may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates.

• levamlodipine

  fedratinib 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.

• levomilnacipran

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

• levonorgestrel oral

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

• linagliptin

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

• lomitapide

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

• lumateperone

  fedratinib will increase the level or effect of lumateperone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce lumateperone dose to 21 mg/day if coadministered with moderate CYP3A4 inhibitors.

• lurasidone

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

• macimorelin

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

• macitentan

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

• maprotiline

  fedratinib will increase the level or effect of maprotiline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• maraviroc

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

• marijuana

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

• mavacamten

  fedratinib will increase the level or effect of mavacamten by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Inititiation of moderate CYP3A4 inhibitors may require decreased mavacamten dose.

• medroxyprogesterone

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

• mefloquine

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

• mestranol

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

• metaxalone

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

• methadone

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

• methamphetamine

  fedratinib will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• methsuximide

  fedratinib will increase the level or effect of methsuximide by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• methylergonovine

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

• methylprednisolone

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

• metoprolol

  fedratinib will increase the level or effect of metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• midazolam

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

• midostaurin

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

• mifepristone

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

• mirtazapine

  fedratinib will increase the level or effect of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of mirtazapine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• modafinil

  fedratinib will increase the level or effect of modafinil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of modafinil by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• montelukast

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

• naldemedine

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

• naloxegol

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

• nebivolol

  fedratinib will increase the level or effect of nebivolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• nefazodone

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

• nelfinavir

  fedratinib will increase the level or effect of nelfinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of nelfinavir by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• netupitant/palonosetron

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

• nevirapine

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

• nicardipine

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

• nifedipine

  fedratinib will increase the level or effect of nifedipine by affecting hepatic enzyme CYP2E1 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• nilotinib

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

• nimodipine

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

• norethindrone

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

• norethindrone acetate

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

• nortriptyline

  fedratinib will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• olaparib

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

• oliceridine

  fedratinib will increase the level or effect of oliceridine by affecting hepatic enzyme CYP2D6 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.
  
  fedratinib 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.

• ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC)

  fedratinib will increase the level or effect of ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• omeprazole

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

• ondansetron

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

• osimertinib

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

• ospemifene

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

• oxycodone

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

• paclitaxel

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

• paclitaxel protein bound

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

• palbociclib

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

• palovarotene

  fedratinib will increase the level or effect of palovarotene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Avoid coadministration of palovarotene, a CYP3A substrate, with moderate CYP3A inhibitors. If unavoidable, reduce palovarotene dose by 50%.

• panobinostat

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

• paricalcitol

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

• paroxetine

  fedratinib will increase the level or effect of paroxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• pazopanib

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

• pentamidine

  fedratinib will increase the level or effect of pentamidine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• perampanel

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

• perphenazine

  fedratinib will increase the level or effect of perphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• phenobarbital

  fedratinib will increase the level or effect of phenobarbital by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• pimavanserin

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

• pimozide

  fedratinib will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of pimozide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• pitolisant

  fedratinib will increase the level or effect of pitolisant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of pitolisant by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• polatuzumab vedotin

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

• pomalidomide

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

• praziquantel

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

• progesterone intravaginal gel

  fedratinib will increase the level or effect of progesterone intravaginal gel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of progesterone intravaginal gel by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• progesterone micronized

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

• progesterone, natural

  fedratinib will increase the level or effect of progesterone, natural by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of progesterone, natural by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• promethazine

  fedratinib will increase the level or effect of promethazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• propafenone

  fedratinib will increase the level or effect of propafenone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• propranolol

  fedratinib will increase the level or effect of propranolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• protriptyline

  fedratinib will increase the level or effect of protriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• quazepam

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

• quetiapine

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

• quinidine

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

• quinine

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

• rabeprazole

  fedratinib will increase the level or effect of rabeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of rabeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• ranolazine

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

• regorafenib

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

• repaglinide

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

• ribociclib

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

• rifabutin

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

• rimegepant

  fedratinib will increase the level or effect of rimegepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Avoid repeating rimegepant dose within 48 hr if coadministered with a moderate CYP3A4 inhibitor.

• riociguat

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

• risperidone

  fedratinib will increase the level or effect of risperidone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• ritonavir

  fedratinib will increase the level or effect of ritonavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of ritonavir by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• rivaroxaban

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

• roflumilast

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

• rolapitant

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

• romidepsin

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

• ropivacaine

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

• rucaparib

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

• ruxolitinib

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

• ruxolitinib topical

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

• salmeterol

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

• saquinavir

  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.

• saxagliptin

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

• sertraline

  fedratinib will increase the level or effect of sertraline by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.
  
  fedratinib will increase the level or effect of sertraline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• sildenafil

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

• simvastatin

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

• siponimod

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

• sirolimus

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

• solifenacin

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

• sonidegib

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

• sorafenib

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

• sparsentan

  fedratinib will increase the level or effect of sparsentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment needed. Monitor blood pressure, serum potassium, edema, and kidney function regularly if sparsentan is coadministered with moderate CYP3A4 inhibitors.

• stiripentol

  fedratinib will increase the level or effect of stiripentol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of stiripentol by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• sufentanil

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

• sufentanil SL

  fedratinib increases and sufentanil SL decreases affecting hepatic/intestinal enzyme CYP3A4 metabolism. Effect of interaction is not clear, use caution. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary..

• sunitinib

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

• suvorexant

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

• tacrolimus

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

• tadalafil

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

• tamoxifen

  fedratinib will increase the level or effect of tamoxifen by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of tamoxifen by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• tamsulosin

  fedratinib will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• tasimelteon

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

• tazemetostat

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

• temsirolimus

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

• teniposide

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

• tetracycline

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

• tezacaftor

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

• theophylline

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

• thioridazine

  fedratinib will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• tiagabine

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

• ticagrelor

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

• ticlopidine

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

• timolol

  fedratinib will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• timolol ophthalmic

  fedratinib will increase the level or effect of timolol ophthalmic by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• tinidazole

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

• tipranavir

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

• tofacitinib

  fedratinib will increase the level or effect of tofacitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of tofacitinib by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• tolterodine

  fedratinib will increase the level or effect of tolterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of tolterodine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• toremifene

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

• trabectedin

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

• tramadol

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

• trazodone

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

• triazolam

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

• trimethoprim

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

• trimipramine

  fedratinib will increase the level or effect of trimipramine by affecting hepatic enzyme CYP2E1 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of trimipramine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.
  
  fedratinib will increase the level or effect of trimipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• ublituximab

  ublituximab and fedratinib both increase immunosuppressive effects; risk of infection. Modify Therapy/Monitor Closely. Owing to potential additive immunosuppressive effects, consider duration of effect and mechanism of action of these therapies if coadministered

• ulipristal

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

• umeclidinium bromide/vilanterol inhaled

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

• valbenazine

  fedratinib will increase the level or effect of valbenazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of valbenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• vandetanib

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

• vardenafil

  fedratinib will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors

• velpatasvir

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

• vemurafenib

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

• venetoclax

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

• venlafaxine

  fedratinib will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• verapamil

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

• vilanterol/fluticasone furoate inhaled

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

• vilazodone

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

• vinblastine

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

• vincristine

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

• vincristine liposomal

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

• vinorelbine

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

• voclosporin

  fedratinib will increase the level or effect of voclosporin by affecting hepatic enzyme CYP2E1 metabolism. Modify Therapy/Monitor Closely. Reduce voclosporin daily dosage to 15.8 mg PO in AM and 7.9 mg PO in PM.

• vorapaxar

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

• voriconazole

  fedratinib will increase the level or effect of voriconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of voriconazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• vortioxetine

  fedratinib will increase the level or effect of vortioxetine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of vortioxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• voxilaprevir

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

• zanubrutinib

  fedratinib will increase the level or effect of zanubrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce zanubrutinib (a CYP3A4 substrate) to 80 mg PO BID to when coadministered with a moderate CYP3A4 inhibitor. Interrupt dose as recommended for adverse reactions. After discontinuing the CYP3A4 inhibitor, resume previous dose of zanubrutinib.

• zolpidem

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

• zonisamide

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

Minor (3)

• acetazolamide

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

• anastrozole

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

• cyclophosphamide

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

• abemaciclib

  Monitor Closely (1)fedratinib will increase the level or effect of abemaciclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• acalabrutinib

  Monitor Closely (1)fedratinib will increase the level or effect of acalabrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• acetazolamide

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

• ado-trastuzumab emtansine

  Monitor Closely (1)fedratinib will increase the level or effect of ado-trastuzumab emtansine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• alfentanil

  Monitor Closely (1)fedratinib will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• alfuzosin

  Monitor Closely (1)fedratinib will increase the level or effect of alfuzosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• alpelisib

  Monitor Closely (1)fedratinib will increase the level or effect of alpelisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• alprazolam

  Monitor Closely (1)fedratinib will increase the level or effect of alprazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• ambrisentan

  Monitor Closely (1)fedratinib will increase the level or effect of ambrisentan by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• amiodarone

  Monitor Closely (2)fedratinib will increase the level or effect of amiodarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of amiodarone by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (1)amiodarone 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.

• amitriptyline

  Monitor Closely (1)fedratinib will increase the level or effect of amitriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• amlodipine

  Monitor Closely (1)fedratinib will increase the level or effect of amlodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• amobarbital

  Serious - Use Alternative (1)amobarbital will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• amoxapine

  Monitor Closely (1)fedratinib will increase the level or effect of amoxapine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• anastrozole

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

• apalutamide

  Monitor Closely (1)fedratinib will increase the level or effect of apalutamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)apalutamide will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• apixaban

  Monitor Closely (1)fedratinib will increase the level or effect of apixaban by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• apomorphine

  Serious - Use Alternative (1)apomorphine 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.

• apremilast

  Monitor Closely (1)fedratinib will increase the level or effect of apremilast by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• aprepitant

  Monitor Closely (1)fedratinib will increase the level or effect of aprepitant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)aprepitant 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.

• aripiprazole

  Monitor Closely (2)fedratinib will increase the level or effect of aripiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of aripiprazole by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• armodafinil

  Monitor Closely (1)fedratinib will increase the level or effect of armodafinil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)armodafinil will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a moderate CYP3A4 inducer with fedratinib has not been studied.

• atazanavir

  Monitor Closely (1)fedratinib will increase the level or effect of atazanavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)atazanavir 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.

• atogepant

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

• atomoxetine

  Monitor Closely (1)fedratinib will increase the level or effect of atomoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• atorvastatin

  Monitor Closely (1)fedratinib will increase the level or effect of atorvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• avanafil

  Monitor Closely (1)fedratinib will increase the level or effect of avanafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• avapritinib

  Serious - Use Alternative (1)fedratinib 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 moderate CYP3A4 inhibitors. If unable to avoid, reduce avapritinib starting dose. See drug monograph Dosage Modifications.

• axitinib

  Monitor Closely (1)fedratinib will increase the level or effect of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• azelastine

  Serious - Use Alternative (1)azelastine 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.

• bedaquiline

  Monitor Closely (1)fedratinib will increase the level or effect of bedaquiline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• belzutifan

  Monitor Closely (1)belzutifan will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If unable to avoid coadministration of belzutifan with sensitive CYP3A4 substrates, consider increasing the sensitive CYP3A4 substrate dose in accordance with its prescribing information.

• benzhydrocodone/acetaminophen

  Monitor Closely (1)fedratinib will increase the level or effect of benzhydrocodone/acetaminophen by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• benzphetamine

  Monitor Closely (1)fedratinib will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• bexarotene

  Serious - Use Alternative (1)bexarotene will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a moderate CYP3A4 inducer with fedratinib has not been studied.

• bortezomib

  Monitor Closely (2)fedratinib will increase the level or effect of bortezomib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of bortezomib by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (1)bortezomib 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.

• bosentan

  Monitor Closely (1)fedratinib will increase the level or effect of bosentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)bosentan will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• bosutinib

  Monitor Closely (1)fedratinib will increase the level or effect of bosutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• brentuximab vedotin

  Monitor Closely (1)fedratinib will increase the level or effect of brentuximab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• brexpiprazole

  Monitor Closely (2)fedratinib will increase the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• brigatinib

  Monitor Closely (1)fedratinib will increase the level or effect of brigatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)brigatinib will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a moderate CYP3A4 inducer with fedratinib has not been studied.

• bromocriptine

  Monitor Closely (1)fedratinib will increase the level or effect of bromocriptine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• budesonide

  Monitor Closely (1)fedratinib will increase the level or effect of budesonide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• buprenorphine

  Monitor Closely (1)fedratinib will increase the level or effect of buprenorphine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• buprenorphine subdermal implant

  Monitor Closely (1)fedratinib will increase the level or effect of buprenorphine subdermal implant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• buprenorphine transdermal

  Monitor Closely (1)fedratinib will increase the level or effect of buprenorphine transdermal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• buspirone

  Monitor Closely (1)fedratinib will increase the level or effect of buspirone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• busulfan

  Monitor Closely (1)fedratinib will increase the level or effect of busulfan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• butabarbital

  Serious - Use Alternative (1)butabarbital will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• butalbital

  Serious - Use Alternative (1)butalbital will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• cabozantinib

  Monitor Closely (1)fedratinib will increase the level or effect of cabozantinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• calcifediol

  Monitor Closely (1)fedratinib will increase the level or effect of calcifediol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• calcitriol

  Monitor Closely (1)fedratinib will increase the level or effect of calcitriol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• capivasertib

  Monitor Closely (1)fedratinib will increase the level or effect of capivasertib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce capivasertib dose if coadministered with moderate CYP3A inhibitors.

• captopril

  Monitor Closely (1)fedratinib will increase the level or effect of captopril by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• carbamazepine

  Monitor Closely (1)fedratinib will increase the level or effect of carbamazepine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)carbamazepine will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• cariprazine

  Monitor Closely (1)fedratinib will increase the level or effect of cariprazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• carisoprodol

  Monitor Closely (1)fedratinib will increase the level or effect of carisoprodol by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• carvedilol

  Monitor Closely (1)fedratinib will increase the level or effect of carvedilol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• cenobamate

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

• ceritinib

  Monitor Closely (1)fedratinib will increase the level or effect of ceritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)ceritinib will increase the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• chloramphenicol

  Serious - Use Alternative (2)chloramphenicol 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.
  
  chloramphenicol 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.

• chlordiazepoxide

  Monitor Closely (1)fedratinib will increase the level or effect of chlordiazepoxide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• chloroquine

  Monitor Closely (2)fedratinib will increase the level or effect of chloroquine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of chloroquine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• chlorpheniramine

  Monitor Closely (1)fedratinib will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• chlorpromazine

  Monitor Closely (1)fedratinib will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• ciclesonide inhaled

  Monitor Closely (1)fedratinib will increase the level or effect of ciclesonide inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• ciclesonide intranasal

  Monitor Closely (1)fedratinib will increase the level or effect of ciclesonide intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• cilostazol

  Monitor Closely (1)fedratinib will increase the level or effect of cilostazol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• cimetidine

  Serious - Use Alternative (1)cimetidine 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.

• cinacalcet

  Monitor Closely (1)fedratinib will increase the level or effect of cinacalcet by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• citalopram

  Monitor Closely (2)fedratinib will increase the level or effect of citalopram by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.
  
  fedratinib will increase the level or effect of citalopram by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• clarithromycin

  Monitor Closely (1)fedratinib will increase the level or effect of clarithromycin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)clarithromycin 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.

• clobazam

  Monitor Closely (1)fedratinib will increase the level or effect of clobazam by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (1)clobazam will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a moderate CYP3A4 inducer with fedratinib has not been studied.

• clomipramine

  Monitor Closely (2)fedratinib will increase the level or effect of clomipramine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.
  
  fedratinib will increase the level or effect of clomipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• clorazepate

  Monitor Closely (1)fedratinib will increase the level or effect of clorazepate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• clozapine

  Serious - Use Alternative (1)clozapine 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.

• cobicistat

  Monitor Closely (1)fedratinib will increase the level or effect of cobicistat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)cobicistat 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.

• cobimetinib

  Monitor Closely (1)fedratinib will increase the level or effect of cobimetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• cocaine topical

  Monitor Closely (1)fedratinib will increase the level or effect of cocaine topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• codeine

  Monitor Closely (1)fedratinib will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• colchicine

  Monitor Closely (1)fedratinib will increase the level or effect of colchicine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• conivaptan

  Monitor Closely (1)fedratinib will increase the level or effect of conivaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)conivaptan 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.

• conjugated estrogens

  Monitor Closely (1)fedratinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• copanlisib

  Monitor Closely (1)fedratinib will increase the level or effect of copanlisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• crizotinib

  Monitor Closely (1)fedratinib will increase the level or effect of crizotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• cyclophosphamide

  Monitor Closely (1)fedratinib will increase the level or effect of cyclophosphamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Minor (1)cyclophosphamide will increase the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• cyclosporine

  Monitor Closely (1)fedratinib will increase the level or effect of cyclosporine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• dabrafenib

  Monitor Closely (1)fedratinib will increase the level or effect of dabrafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)dabrafenib will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• dantrolene

  Monitor Closely (1)fedratinib will increase the level or effect of dantrolene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• dapsone

  Monitor Closely (1)fedratinib will increase the level or effect of dapsone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• daridorexant

  Monitor Closely (1)fedratinib will increase the level or effect of daridorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Daridorexant dose should not exceed 25 mg per night when coadministered with moderate CYP3A4 inhibitors.

• darifenacin

  Monitor Closely (1)fedratinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• darolutamide

  Monitor Closely (1)fedratinib will increase the level or effect of darolutamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• darunavir

  Monitor Closely (1)fedratinib will increase the level or effect of darunavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)darunavir 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.

• dasatinib

  Monitor Closely (1)fedratinib will increase the level or effect of dasatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• deflazacort

  Monitor Closely (1)fedratinib will increase the level or effect of deflazacort by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• desipramine

  Monitor Closely (1)fedratinib will increase the level or effect of desipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• deutetrabenazine

  Monitor Closely (1)fedratinib will increase the level or effect of deutetrabenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• dexamethasone

  Monitor Closely (1)fedratinib will increase the level or effect of dexamethasone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• dexlansoprazole

  Monitor Closely (2)fedratinib will increase the level or effect of dexlansoprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of dexlansoprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (1)dexlansoprazole 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.

• diazepam

  Monitor Closely (1)fedratinib will increase the level or effect of diazepam by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (1)diazepam 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.

• diazepam intranasal

  Monitor Closely (2)fedratinib will increase the level or effect of diazepam intranasal by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Strong or moderate CYP2C19 inhibitors may decrease rate of diazepam elimination, thereby increasing adverse reactions to diazepam.
  
  fedratinib 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.

• dihydroergotamine

  Monitor Closely (1)fedratinib will increase the level or effect of dihydroergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• dihydroergotamine inhaled

  Monitor Closely (1)fedratinib will increase the level or effect of dihydroergotamine inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• diltiazem

  Monitor Closely (1)fedratinib will increase the level or effect of diltiazem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• disopyramide

  Monitor Closely (1)fedratinib will increase the level or effect of disopyramide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• docetaxel

  Monitor Closely (1)fedratinib will increase the level or effect of docetaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• doravirine

  Monitor Closely (1)fedratinib will increase the level or effect of doravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• doxepin

  Monitor Closely (2)fedratinib will increase the level or effect of doxepin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• doxepin cream

  Monitor Closely (1)fedratinib will increase the level or effect of doxepin cream by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• doxorubicin

  Monitor Closely (2)fedratinib will increase the level or effect of doxorubicin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of doxorubicin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• doxorubicin liposomal

  Monitor Closely (2)fedratinib will increase the level or effect of doxorubicin liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of doxorubicin liposomal by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• dronabinol

  Monitor Closely (1)fedratinib will increase the level or effect of dronabinol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• dronedarone

  Monitor Closely (1)fedratinib will increase the level or effect of dronedarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• drospirenone

  Serious - Use Alternative (1)drospirenone 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.

• duloxetine

  Monitor Closely (1)fedratinib will increase the level or effect of duloxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• duvelisib

  Monitor Closely (1)fedratinib will increase the level or effect of duvelisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• efavirenz

  Monitor Closely (1)fedratinib will increase the level or effect of efavirenz by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)efavirenz will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• elacestrant

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

• elagolix

  Monitor Closely (2)fedratinib will increase the level or effect of elagolix by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  elagolix decreases levels of fedratinib 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

  Monitor Closely (1)fedratinib will increase the level or effect of elbasvir/grazoprevir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• eletriptan

  Monitor Closely (1)fedratinib will increase the level or effect of eletriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• eliglustat

  Monitor Closely (2)fedratinib will increase the level or effect of eliglustat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of eliglustat by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• encorafenib

  Monitor Closely (1)fedratinib will increase the level or effect of encorafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)encorafenib will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a moderate CYP3A4 inducer with fedratinib has not been studied.

• entrectinib

  Monitor Closely (1)fedratinib will increase the level or effect of entrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• enzalutamide

  Monitor Closely (1)fedratinib will increase the level or effect of enzalutamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)enzalutamide will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• eplerenone

  Monitor Closely (1)fedratinib will increase the level or effect of eplerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• ergoloid mesylates

  Monitor Closely (1)fedratinib will increase the level or effect of ergoloid mesylates by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• ergotamine

  Monitor Closely (1)fedratinib will increase the level or effect of ergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• erlotinib

  Monitor Closely (1)fedratinib will increase the level or effect of erlotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• erythromycin base

  Monitor Closely (1)fedratinib will increase the level or effect of erythromycin base by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• erythromycin ethylsuccinate

  Monitor Closely (1)fedratinib will increase the level or effect of erythromycin ethylsuccinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• erythromycin lactobionate

  Monitor Closely (1)fedratinib will increase the level or effect of erythromycin lactobionate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• erythromycin stearate

  Monitor Closely (1)fedratinib will increase the level or effect of erythromycin stearate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• escitalopram

  Monitor Closely (2)fedratinib will increase the level or effect of escitalopram by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of escitalopram by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• eslicarbazepine acetate

  Serious - Use Alternative (1)eslicarbazepine acetate will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a moderate CYP3A4 inducer with fedratinib has not been studied.

• esomeprazole

  Monitor Closely (2)fedratinib will increase the level or effect of esomeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of esomeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• estradiol

  Monitor Closely (1)fedratinib will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• estrogens conjugated synthetic

  Monitor Closely (1)fedratinib will increase the level or effect of estrogens conjugated synthetic by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• estrogens esterified

  Monitor Closely (1)fedratinib will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• estropipate

  Monitor Closely (1)fedratinib will increase the level or effect of estropipate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• eszopiclone

  Monitor Closely (1)fedratinib will increase the level or effect of eszopiclone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• ethinylestradiol

  Monitor Closely (1)fedratinib will increase the level or effect of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)ethinylestradiol 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.

• etoposide

  Monitor Closely (1)fedratinib will increase the level or effect of etoposide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• etrasimod

  Serious - Use Alternative (1)etrasimod, fedratinib. Either increases effects of the other by immunosuppressive effects; risk of infection. Avoid or Use Alternate Drug. Risk of additive immune system effects with etrasimod has not been studied in combination with antineoplastic, immune-modulating, or noncorticosteroid immunosuppressive therapies. Avoid coadministration during and in the weeks following administration of etrasimod.

• etravirine

  Monitor Closely (2)fedratinib will increase the level or effect of etravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of etravirine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (1)etravirine will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• everolimus

  Monitor Closely (1)fedratinib will increase the level or effect of everolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• exemestane

  Monitor Closely (1)fedratinib will increase the level or effect of exemestane by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• felbamate

  Monitor Closely (1)fedratinib will increase the level or effect of felbamate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• felodipine

  Serious - Use Alternative (1)felodipine 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.

• fenofibrate

  Monitor Closely (1)fedratinib will increase the level or effect of fenofibrate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• fenofibrate micronized

  Monitor Closely (1)fedratinib will increase the level or effect of fenofibrate micronized by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• fenofibric acid

  Monitor Closely (1)fedratinib will increase the level or effect of fenofibric acid by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• fentanyl

  Monitor Closely (1)fedratinib will increase the level or effect of fentanyl by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• fentanyl intranasal

  Monitor Closely (1)fedratinib will increase the level or effect of fentanyl intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• fentanyl transdermal

  Monitor Closely (1)fedratinib will increase the level or effect of fentanyl transdermal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• fentanyl transmucosal

  Monitor Closely (1)fedratinib will increase the level or effect of fentanyl transmucosal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• fexinidazole

  Serious - Use Alternative (1)fexinidazole will increase the level or effect of fedratinib 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

  Monitor Closely (1)fedratinib will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or moderate CYP3A4 inhibitors. Adjust finererone dosage as needed.

• flecainide

  Monitor Closely (1)fedratinib will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• flibanserin

  Monitor Closely (2)fedratinib will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of flibanserin by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• fluconazole

  Serious - Use Alternative (1)fluconazole 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.

• flunisolide intranasal

  Monitor Closely (1)fedratinib will increase the level or effect of flunisolide intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• fluoxetine

  Monitor Closely (1)fedratinib will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.Serious - Use Alternative (1)fluoxetine 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.

• fluphenazine

  Monitor Closely (1)fedratinib will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• flurazepam

  Monitor Closely (1)fedratinib will increase the level or effect of flurazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• flutamide

  Monitor Closely (1)fedratinib will increase the level or effect of flutamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• fluticasone furoate

  Monitor Closely (1)fedratinib will increase the level or effect of fluticasone furoate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• fluticasone inhaled

  Monitor Closely (1)fedratinib will increase the level or effect of fluticasone inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• fluticasone intranasal

  Monitor Closely (1)fedratinib will increase the level or effect of fluticasone intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• fluvoxamine

  Monitor Closely (1)fedratinib will increase the level or effect of fluvoxamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of CYP2D6 substrates as necessarySerious - Use Alternative (1)fluvoxamine 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 coadminitration of a dual CYP3A4 and CYP2C19 inhibitor with fedratinib not studied

• fosamprenavir

  Monitor Closely (1)fedratinib will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• fosaprepitant

  Monitor Closely (1)fedratinib will increase the level or effect of fosaprepitant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)fosaprepitant 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.

• fosphenytoin

  Monitor Closely (1)fedratinib will increase the level or effect of fosphenytoin by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (1)fosphenytoin will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• fostamatinib

  Monitor Closely (1)fedratinib will increase the level or effect of fostamatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• gefitinib

  Monitor Closely (1)fedratinib will increase the level or effect of gefitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• gepirone

  Monitor Closely (1)fedratinib will increase the level or effect of gepirone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce gepirone dose by 50% when used concomitantly with a moderate CYP3A4 inhibitor.

• glasdegib

  Monitor Closely (1)fedratinib will increase the level or effect of glasdegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• glecaprevir/pibrentasvir

  Monitor Closely (1)fedratinib will increase the level or effect of glecaprevir/pibrentasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• grapefruit

  Serious - Use Alternative (1)grapefruit 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.

• guanfacine

  Monitor Closely (1)fedratinib will increase the level or effect of guanfacine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• haloperidol

  Monitor Closely (2)fedratinib will increase the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• hydrocodone

  Monitor Closely (1)fedratinib will increase the level or effect of hydrocodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• hydroxyprogesterone caproate (DSC)

  Monitor Closely (1)fedratinib will increase the level or effect of hydroxyprogesterone caproate (DSC) by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• ibrutinib

  Monitor Closely (1)fedratinib will increase the level or effect of ibrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• idelalisib

  Monitor Closely (1)fedratinib will increase the level or effect of idelalisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)idelalisib 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.

• ifosfamide

  Monitor Closely (2)fedratinib will increase the level or effect of ifosfamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of ifosfamide by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• iloperidone

  Monitor Closely (1)fedratinib will increase the level or effect of iloperidone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• imatinib

  Monitor Closely (1)fedratinib will increase the level or effect of imatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)imatinib 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.

• imipramine

  Monitor Closely (2)fedratinib will increase the level or effect of imipramine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.
  
  fedratinib will increase the level or effect of imipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• indinavir

  Monitor Closely (1)fedratinib will increase the level or effect of indinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (2)indinavir 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.
  
  indinavir 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.

• infigratinib

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

• irinotecan

  Monitor Closely (1)fedratinib will increase the level or effect of irinotecan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• irinotecan liposomal

  Monitor Closely (1)fedratinib will increase the level or effect of irinotecan liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• isavuconazonium sulfate

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

• isoniazid

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

• isosorbide dinitrate

  Monitor Closely (1)fedratinib will increase the level or effect of isosorbide dinitrate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• isosorbide mononitrate

  Monitor Closely (1)fedratinib will increase the level or effect of isosorbide mononitrate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• isradipine

  Monitor Closely (1)fedratinib will increase the level or effect of isradipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• istradefylline

  Monitor Closely (1)istradefylline will increase the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.

• itraconazole

  Monitor Closely (1)fedratinib will increase the level or effect of itraconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)itraconazole 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.

• ivacaftor

  Monitor Closely (1)fedratinib 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 moderate CYP3A4 inhibitors. See specific ivacaftor-containing product for precise dosage modification.

• ivosidenib

  Monitor Closely (1)fedratinib will increase the level or effect of ivosidenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)ivosidenib will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• ixabepilone

  Monitor Closely (1)fedratinib will increase the level or effect of ixabepilone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• ixazomib

  Monitor Closely (1)fedratinib will increase the level or effect of ixazomib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• ketamine

  Monitor Closely (1)fedratinib will increase the level or effect of ketamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• ketoconazole

  Serious - Use Alternative (2)ketoconazole 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.
  
  ketoconazole 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.

• lacosamide

  Monitor Closely (1)fedratinib will increase the level or effect of lacosamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• lansoprazole

  Monitor Closely (2)fedratinib will increase the level or effect of lansoprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of lansoprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (1)lansoprazole 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.

• lapatinib

  Monitor Closely (1)fedratinib will increase the level or effect of lapatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• larotrectinib

  Monitor Closely (1)fedratinib will increase the level or effect of larotrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)larotrectinib 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.

• lefamulin

  Monitor Closely (1)fedratinib will increase the level or effect of lefamulin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor for adverse effects if lefamulin is coadministered with moderate CYP3A inhibitors.

• lemborexant

  Serious - Use Alternative (1)fedratinib 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.

• lenacapavir

  Monitor Closely (1)lenacapavir will increase the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir (a moderate CYP3A4 inhibitor) may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates.

• lenvatinib

  Serious - Use Alternative (1)lenvatinib 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.

• levamlodipine

  Monitor Closely (1)fedratinib 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.

• levoketoconazole

  Serious - Use Alternative (2)levoketoconazole 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.
  
  levoketoconazole 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.

• levomilnacipran

  Monitor Closely (1)fedratinib will increase the level or effect of levomilnacipran by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• levonorgestrel oral

  Monitor Closely (1)fedratinib will increase the level or effect of levonorgestrel oral by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• linagliptin

  Monitor Closely (1)fedratinib will increase the level or effect of linagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• lomitapide

  Monitor Closely (1)fedratinib will increase the level or effect of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• lonafarnib

  Contraindicated (1)fedratinib 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

  Serious - Use Alternative (1)lopinavir 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.

• lorlatinib

  Serious - Use Alternative (1)lorlatinib will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• losartan

  Serious - Use Alternative (1)losartan 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.

• lumacaftor/ivacaftor

  Serious - Use Alternative (1)lumacaftor/ivacaftor will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• lumateperone

  Monitor Closely (1)fedratinib will increase the level or effect of lumateperone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce lumateperone dose to 21 mg/day if coadministered with moderate CYP3A4 inhibitors.

• lurasidone

  Monitor Closely (1)fedratinib will increase the level or effect of lurasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• lurbinectedin

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

• macimorelin

  Monitor Closely (1)fedratinib will increase the level or effect of macimorelin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• macitentan

  Monitor Closely (1)fedratinib will increase the level or effect of macitentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• maprotiline

  Monitor Closely (1)fedratinib will increase the level or effect of maprotiline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• maraviroc

  Monitor Closely (1)fedratinib will increase the level or effect of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• marijuana

  Monitor Closely (1)fedratinib will increase the level or effect of marijuana by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• mavacamten

  Contraindicated (1)fedratinib will increase the level or effect of mavacamten by affecting hepatic enzyme CYP2C19 metabolism. Contraindicated. Strong or moderate CYP2C19 inhibitors may increase mavacamten systemic exposure, resulting in heart failure due to systolic dysfunction. Monitor Closely (1)fedratinib will increase the level or effect of mavacamten by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Inititiation of moderate CYP3A4 inhibitors may require decreased mavacamten dose.

• medroxyprogesterone

  Monitor Closely (1)fedratinib will increase the level or effect of medroxyprogesterone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• mefloquine

  Monitor Closely (1)fedratinib will increase the level or effect of mefloquine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• mestranol

  Monitor Closely (1)fedratinib will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)mestranol 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.

• metaxalone

  Monitor Closely (1)fedratinib will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• methadone

  Monitor Closely (1)fedratinib will increase the level or effect of methadone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• methamphetamine

  Monitor Closely (1)fedratinib will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• methimazole

  Serious - Use Alternative (1)methimazole 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.

• methoxsalen

  Serious - Use Alternative (1)methoxsalen 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.

• methsuximide

  Monitor Closely (1)fedratinib will increase the level or effect of methsuximide by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• methylergonovine

  Monitor Closely (1)fedratinib will increase the level or effect of methylergonovine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• methylprednisolone

  Monitor Closely (1)fedratinib will increase the level or effect of methylprednisolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• metoprolol

  Monitor Closely (1)fedratinib will increase the level or effect of metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• midazolam

  Monitor Closely (1)fedratinib will increase the level or effect of midazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• midostaurin

  Monitor Closely (1)fedratinib will increase the level or effect of midostaurin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• mifepristone

  Monitor Closely (1)fedratinib will increase the level or effect of mifepristone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)mifepristone 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.

• mirtazapine

  Monitor Closely (2)fedratinib will increase the level or effect of mirtazapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of mirtazapine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• mitotane

  Serious - Use Alternative (1)mitotane will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• mobocertinib

  Serious - Use Alternative (1)fedratinib will increase the level or effect of mobocertinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If use of moderate CYP3A4 inhibitor unavoidable, reduce mobocertinib dose by ~50% (eg, 160 to 80 mg); closely monitor QTc interval.

• modafinil

  Monitor Closely (2)fedratinib will increase the level or effect of modafinil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of modafinil by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (1)modafinil 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.

• montelukast

  Monitor Closely (1)fedratinib will increase the level or effect of montelukast by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• nafcillin

  Serious - Use Alternative (1)nafcillin will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• naldemedine

  Monitor Closely (1)fedratinib will increase the level or effect of naldemedine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• naloxegol

  Monitor Closely (1)fedratinib will increase the level or effect of naloxegol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• nebivolol

  Monitor Closely (1)fedratinib will increase the level or effect of nebivolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• nefazodone

  Monitor Closely (1)fedratinib will increase the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)nefazodone 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.

• nelfinavir

  Monitor Closely (2)fedratinib will increase the level or effect of nelfinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of nelfinavir by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (2)nelfinavir 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.
  
  nelfinavir 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.

• netupitant/palonosetron

  Monitor Closely (1)fedratinib will increase the level or effect of netupitant/palonosetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• nevirapine

  Monitor Closely (1)fedratinib will increase the level or effect of nevirapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• nicardipine

  Monitor Closely (1)fedratinib will increase the level or effect of nicardipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)nicardipine 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.

• nifedipine

  Monitor Closely (1)fedratinib will increase the level or effect of nifedipine by affecting hepatic enzyme CYP2E1 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• nilotinib

  Monitor Closely (1)fedratinib will increase the level or effect of nilotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• nimodipine

  Monitor Closely (1)fedratinib will increase the level or effect of nimodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• nirogacestat

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

• norethindrone

  Monitor Closely (1)fedratinib will increase the level or effect of norethindrone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• norethindrone acetate

  Monitor Closely (1)fedratinib will increase the level or effect of norethindrone acetate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• nortriptyline

  Monitor Closely (1)fedratinib will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• olanzapine

  Serious - Use Alternative (1)olanzapine 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.

• olaparib

  Monitor Closely (1)fedratinib will increase the level or effect of olaparib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• oliceridine

  Monitor Closely (2)fedratinib will increase the level or effect of oliceridine by affecting hepatic enzyme CYP2D6 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.
  
  fedratinib 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.

• omaveloxolone

  Serious - Use Alternative (1)fedratinib will increase the level or effect of omaveloxolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unavoidable, reduce omaveloxolone dose to 100 mg/day. Closely monitor for adverse effects. If adverse effects emerge, further reduce to 50 mg/day.

• ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC)

  Monitor Closely (1)fedratinib will increase the level or effect of ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• omeprazole

  Monitor Closely (1)fedratinib will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)omeprazole 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.

• ondansetron

  Monitor Closely (1)fedratinib will increase the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• orphenadrine

  Serious - Use Alternative (1)orphenadrine 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.

• osimertinib

  Monitor Closely (1)fedratinib will increase the level or effect of osimertinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• ospemifene

  Monitor Closely (1)fedratinib will increase the level or effect of ospemifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• oxycodone

  Monitor Closely (1)fedratinib will increase the level or effect of oxycodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• paclitaxel

  Monitor Closely (1)fedratinib will increase the level or effect of paclitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• paclitaxel protein bound

  Monitor Closely (1)fedratinib will increase the level or effect of paclitaxel protein bound by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• pacritinib

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

• palbociclib

  Monitor Closely (1)fedratinib will increase the level or effect of palbociclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• palovarotene

  Monitor Closely (1)fedratinib will increase the level or effect of palovarotene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Avoid coadministration of palovarotene, a CYP3A substrate, with moderate CYP3A inhibitors. If unavoidable, reduce palovarotene dose by 50%.

• panobinostat

  Monitor Closely (1)fedratinib will increase the level or effect of panobinostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• paricalcitol

  Monitor Closely (1)fedratinib will increase the level or effect of paricalcitol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• paroxetine

  Monitor Closely (1)fedratinib will increase the level or effect of paroxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.Serious - Use Alternative (1)paroxetine 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.

• pazopanib

  Monitor Closely (1)fedratinib will increase the level or effect of pazopanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• pemigatinib

  Serious - Use Alternative (1)fedratinib 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

  Monitor Closely (1)fedratinib will increase the level or effect of pentamidine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (1)pentamidine 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.

• pentobarbital

  Serious - Use Alternative (1)pentobarbital will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• perampanel

  Monitor Closely (1)fedratinib will increase the level or effect of perampanel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• perphenazine

  Monitor Closely (1)fedratinib will increase the level or effect of perphenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• pexidartinib

  Serious - Use Alternative (1)fedratinib 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 (1)fedratinib will increase the level or effect of phenobarbital by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (1)phenobarbital will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• phenytoin

  Serious - Use Alternative (1)phenytoin will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• pimavanserin

  Monitor Closely (1)fedratinib will increase the level or effect of pimavanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• pimozide

  Monitor Closely (2)fedratinib will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of pimozide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.Serious - Use Alternative (1)pimozide 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.

• pitolisant

  Monitor Closely (2)fedratinib will increase the level or effect of pitolisant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of pitolisant by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• polatuzumab vedotin

  Monitor Closely (1)fedratinib will increase the level or effect of polatuzumab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• pomalidomide

  Monitor Closely (1)fedratinib will increase the level or effect of pomalidomide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• posaconazole

  Serious - Use Alternative (1)posaconazole 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.

• praziquantel

  Monitor Closely (1)fedratinib will increase the level or effect of praziquantel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• primidone

  Serious - Use Alternative (1)primidone will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• progesterone intravaginal gel

  Monitor Closely (2)fedratinib will increase the level or effect of progesterone intravaginal gel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of progesterone intravaginal gel by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (1)progesterone intravaginal gel 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.

• progesterone micronized

  Monitor Closely (1)fedratinib will increase the level or effect of progesterone micronized by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)progesterone micronized 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.

• progesterone, natural

  Monitor Closely (2)fedratinib will increase the level or effect of progesterone, natural by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of progesterone, natural by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (1)progesterone, natural 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.

• promethazine

  Monitor Closely (1)fedratinib will increase the level or effect of promethazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• propafenone

  Monitor Closely (1)fedratinib will increase the level or effect of propafenone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• propofol

  Serious - Use Alternative (1)propofol 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.

• propranolol

  Monitor Closely (1)fedratinib will increase the level or effect of propranolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• protriptyline

  Monitor Closely (1)fedratinib will increase the level or effect of protriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• quazepam

  Monitor Closely (1)fedratinib will increase the level or effect of quazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• quetiapine

  Monitor Closely (1)fedratinib will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• quinidine

  Monitor Closely (1)fedratinib will increase the level or effect of quinidine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• quinine

  Monitor Closely (1)fedratinib will increase the level or effect of quinine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• rabeprazole

  Monitor Closely (2)fedratinib will increase the level or effect of rabeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of rabeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (1)rabeprazole 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.

• ranolazine

  Monitor Closely (1)fedratinib will increase the level or effect of ranolazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• regorafenib

  Monitor Closely (1)fedratinib will increase the level or effect of regorafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• repaglinide

  Monitor Closely (1)fedratinib will increase the level or effect of repaglinide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• repotrectinib

  Serious - Use Alternative (1)fedratinib will increase the level or effect of repotrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Discontinue strong or moderate CYP3A inhibitors and wait 3-5 elimination half-lives before initiating repotrectinib.

• ribociclib

  Monitor Closely (2)fedratinib will increase the level or effect of ribociclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  ribociclib will increase the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• rifabutin

  Monitor Closely (1)fedratinib will increase the level or effect of rifabutin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)rifabutin will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• rifampin

  Serious - Use Alternative (1)rifampin will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• rifapentine

  Serious - Use Alternative (1)rifapentine will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• rimegepant

  Monitor Closely (1)fedratinib will increase the level or effect of rimegepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Avoid repeating rimegepant dose within 48 hr if coadministered with a moderate CYP3A4 inhibitor.

• riociguat

  Monitor Closely (1)fedratinib will increase the level or effect of riociguat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• risperidone

  Monitor Closely (1)fedratinib will increase the level or effect of risperidone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• ritonavir

  Monitor Closely (2)fedratinib will increase the level or effect of ritonavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of ritonavir by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.Serious - Use Alternative (2)ritonavir 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.
  
  ritonavir 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.

• rivaroxaban

  Monitor Closely (1)fedratinib will increase the level or effect of rivaroxaban by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• roflumilast

  Monitor Closely (1)fedratinib will increase the level or effect of roflumilast by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• rolapitant

  Monitor Closely (1)fedratinib will increase the level or effect of rolapitant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• romidepsin

  Monitor Closely (1)fedratinib will increase the level or effect of romidepsin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• ropivacaine

  Monitor Closely (1)fedratinib will increase the level or effect of ropivacaine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• rucaparib

  Monitor Closely (1)rucaparib will increase the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.

• ruxolitinib

  Monitor Closely (1)fedratinib will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• ruxolitinib topical

  Monitor Closely (1)fedratinib will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• salmeterol

  Monitor Closely (1)fedratinib will increase the level or effect of salmeterol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• saquinavir

  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.

• saxagliptin

  Monitor Closely (1)fedratinib will increase the level or effect of saxagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• secobarbital

  Serious - Use Alternative (1)secobarbital will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• selegiline

  Serious - Use Alternative (1)selegiline 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.

• selegiline transdermal

  Serious - Use Alternative (1)selegiline transdermal 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.

• selumetinib

  Serious - Use Alternative (1)fedratinib 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

  Monitor Closely (2)fedratinib will increase the level or effect of sertraline by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.
  
  fedratinib will increase the level or effect of sertraline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.Serious - Use Alternative (1)sertraline 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.

• sildenafil

  Monitor Closely (1)fedratinib will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• simvastatin

  Monitor Closely (1)fedratinib will increase the level or effect of simvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• siponimod

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

• sirolimus

  Monitor Closely (1)fedratinib will increase the level or effect of sirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• solifenacin

  Monitor Closely (1)fedratinib will increase the level or effect of solifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• sonidegib

  Monitor Closely (1)fedratinib will increase the level or effect of sonidegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• sorafenib

  Monitor Closely (1)fedratinib will increase the level or effect of sorafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• sparsentan

  Monitor Closely (1)fedratinib will increase the level or effect of sparsentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No dosage adjustment needed. Monitor blood pressure, serum potassium, edema, and kidney function regularly if sparsentan is coadministered with moderate CYP3A4 inhibitors.

• St John's Wort

  Serious - Use Alternative (1)St John's Wort will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

• stiripentol

  Monitor Closely (2)fedratinib will increase the level or effect of stiripentol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of stiripentol by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (1)stiripentol 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.

• sufentanil

  Monitor Closely (1)fedratinib will increase the level or effect of sufentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• sufentanil SL

  Monitor Closely (1)fedratinib increases and sufentanil SL decreases affecting hepatic/intestinal enzyme CYP3A4 metabolism. Effect of interaction is not clear, use caution. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary..

• sunitinib

  Monitor Closely (1)fedratinib will increase the level or effect of sunitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• suvorexant

  Monitor Closely (1)fedratinib will increase the level or effect of suvorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• tacrolimus

  Monitor Closely (1)fedratinib will increase the level or effect of tacrolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• tadalafil

  Monitor Closely (1)fedratinib will increase the level or effect of tadalafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• tamoxifen

  Monitor Closely (2)fedratinib will increase the level or effect of tamoxifen by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of tamoxifen by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• tamsulosin

  Monitor Closely (2)fedratinib will increase the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• tasimelteon

  Monitor Closely (1)fedratinib will increase the level or effect of tasimelteon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• tazemetostat

  Monitor Closely (1)tazemetostat will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)fedratinib will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of tazemetostat with moderate CYP3A4 inhibitors. If coadministration is unavoidable, reduce tazemetostat current dose (see drug monograph Dosage Modifications).

• telotristat ethyl

  Serious - Use Alternative (1)telotristat ethyl will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a moderate CYP3A4 inducer with fedratinib has not been studied.

• temsirolimus

  Monitor Closely (1)fedratinib will increase the level or effect of temsirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• teniposide

  Monitor Closely (1)fedratinib will increase the level or effect of teniposide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• tetracycline

  Monitor Closely (1)fedratinib will increase the level or effect of tetracycline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• tezacaftor

  Monitor Closely (1)fedratinib will increase the level or effect of tezacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• theophylline

  Monitor Closely (1)fedratinib will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• thioridazine

  Monitor Closely (1)fedratinib will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• tiagabine

  Monitor Closely (1)fedratinib will increase the level or effect of tiagabine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• ticagrelor

  Monitor Closely (1)fedratinib will increase the level or effect of ticagrelor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• ticlopidine

  Monitor Closely (1)fedratinib will increase the level or effect of ticlopidine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• timolol

  Monitor Closely (1)fedratinib will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• timolol ophthalmic

  Monitor Closely (1)fedratinib will increase the level or effect of timolol ophthalmic by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• tinidazole

  Monitor Closely (1)fedratinib will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• tipranavir

  Monitor Closely (1)fedratinib will increase the level or effect of tipranavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)tipranavir 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.

• tofacitinib

  Monitor Closely (2)fedratinib will increase the level or effect of tofacitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of tofacitinib by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.

• tolterodine

  Monitor Closely (2)fedratinib will increase the level or effect of tolterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of tolterodine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• toremifene

  Monitor Closely (1)fedratinib will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• trabectedin

  Monitor Closely (1)fedratinib will increase the level or effect of trabectedin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• tramadol

  Monitor Closely (1)fedratinib will increase the level or effect of tramadol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• tranylcypromine

  Serious - Use Alternative (1)tranylcypromine 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.

• trazodone

  Monitor Closely (1)fedratinib will increase the level or effect of trazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• triazolam

  Monitor Closely (1)fedratinib will increase the level or effect of triazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• trimethoprim

  Monitor Closely (1)fedratinib will increase the level or effect of trimethoprim by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• trimipramine

  Monitor Closely (3)fedratinib will increase the level or effect of trimipramine by affecting hepatic enzyme CYP2E1 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of trimipramine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.
  
  fedratinib will increase the level or effect of trimipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• tucatinib

  Serious - Use Alternative (1)tucatinib will increase the level or effect of fedratinib 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.

• ublituximab

  Monitor Closely (1)ublituximab and fedratinib both increase immunosuppressive effects; risk of infection. Modify Therapy/Monitor Closely. Owing to potential additive immunosuppressive effects, consider duration of effect and mechanism of action of these therapies if coadministered

• ulipristal

  Monitor Closely (1)fedratinib will increase the level or effect of ulipristal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• umeclidinium bromide/vilanterol inhaled

  Monitor Closely (1)fedratinib will increase the level or effect of umeclidinium bromide/vilanterol inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• valbenazine

  Monitor Closely (2)fedratinib will increase the level or effect of valbenazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of valbenazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• valproic acid

  Serious - Use Alternative (1)valproic acid 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.

• vandetanib

  Monitor Closely (1)fedratinib will increase the level or effect of vandetanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• vardenafil

  Monitor Closely (1)fedratinib will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors

• velpatasvir

  Monitor Closely (1)fedratinib will increase the level or effect of velpatasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• vemurafenib

  Monitor Closely (1)fedratinib will increase the level or effect of vemurafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• venetoclax

  Monitor Closely (1)fedratinib will increase the level or effect of venetoclax by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• venlafaxine

  Monitor Closely (2)fedratinib will increase the level or effect of venlafaxine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of venlafaxine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• verapamil

  Monitor Closely (1)fedratinib will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• vilanterol/fluticasone furoate inhaled

  Monitor Closely (1)fedratinib will increase the level or effect of vilanterol/fluticasone furoate inhaled by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• vilazodone

  Monitor Closely (1)fedratinib will increase the level or effect of vilazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• vinblastine

  Monitor Closely (1)fedratinib will increase the level or effect of vinblastine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• vincristine

  Monitor Closely (1)fedratinib will increase the level or effect of vincristine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• vincristine liposomal

  Monitor Closely (1)fedratinib will increase the level or effect of vincristine liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• vinorelbine

  Monitor Closely (1)fedratinib will increase the level or effect of vinorelbine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• voclosporin

  Monitor Closely (1)fedratinib will increase the level or effect of voclosporin by affecting hepatic enzyme CYP2E1 metabolism. Modify Therapy/Monitor Closely. Reduce voclosporin daily dosage to 15.8 mg PO in AM and 7.9 mg PO in PM.

• vorapaxar

  Monitor Closely (1)fedratinib will increase the level or effect of vorapaxar by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• voriconazole

  Monitor Closely (2)fedratinib will increase the level or effect of voriconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of voriconazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2C19 substrates as necessary.Serious - Use Alternative (2)voriconazole 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.
  
  voriconazole 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.

• vortioxetine

  Monitor Closely (2)fedratinib will increase the level or effect of vortioxetine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
  
  fedratinib will increase the level or effect of vortioxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• voxelotor

  Serious - Use Alternative (1)voxelotor will increase the level or effect of fedratinib 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)fedratinib will increase the level or effect of voxilaprevir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• zafirlukast

  Serious - Use Alternative (1)zafirlukast 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.

• zanubrutinib

  Monitor Closely (1)fedratinib will increase the level or effect of zanubrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Reduce zanubrutinib (a CYP3A4 substrate) to 80 mg PO BID to when coadministered with a moderate CYP3A4 inhibitor. Interrupt dose as recommended for adverse reactions. After discontinuing the CYP3A4 inhibitor, resume previous dose of zanubrutinib.

• zolpidem

  Monitor Closely (1)fedratinib will increase the level or effect of zolpidem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• zonisamide

  Monitor Closely (1)fedratinib will increase the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.