Version July 2025
Serious and fatal encephalopathy, including Wernicke, has occurred in patients treated with fedratinib. Wernicke encephalopathy is a neurologic emergency. Assess thiamine levels in all patients prior to starting fedratinib. Do not start fedratinib in patients with thiamine deficiency; replete thiamine prior to treatment initiation. While on treatment, all patients should receive prophylaxis with daily oral thiamine and should have thiamine levels assessed as clinically indicated. If encephalopathy is suspected, immediately discontinue fedratinib and initiate parenteral thiamine. Monitor until symptoms resolve or improve and thiamine levels normalize.
Dosage guidance:
Clinical considerations: Evaluate baseline thiamine levels prior to treatment initiation; do not initiate fedratinib in patients with thiamine deficiency. Replete thiamine prior to fedratinib initiation if thiamine levels are low. Administer oral daily thiamine prophylactically to all patients during therapy; assess levels as clinically indicated. Fedratinib is associated with a moderate or high emetic potential; antiemetics may be recommended to prevent nausea and vomiting (Ref). Patients transitioning from ruxolitinib to fedratinib must taper and discontinue ruxolitinib (refer to ruxolitinib monograph for ruxolitinib taper/discontinuation).
Myelofibrosis: Oral: 400 mg once daily (in patients with a baseline platelet count ≥50,000/mm3).
Missed doses: If a fedratinib dose is missed, the next scheduled dose should be administered the following day. Do not administer 2 doses to make up for the missed dose.
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Kidney function may be estimated based on the Cockcroft-Gault equation.
CrCl ≥30 mL/minute: No initial dosage adjustment necessary. Exposure may be increased with preexisting moderate impairment; monitor for signs/symptoms of toxicity and adjust dose (based on toxicity) if necessary.
CrCl 15 to 29 mL/minute: Reduce fedratinib dose to 200 mg once daily; monitor closely for signs/symptoms of toxicity.
Hepatic impairment prior to treatment initiation:
Mild (total bilirubin ≤ ULN and AST > ULN or total bilirubin 1 to 1.5 times ULN and any AST) to moderate (total bilirubin 1.5 to 3 times ULN and any AST) impairment: There are no dosage adjustments provided in the manufacturer's labeling; however, mild or moderate impairment did not have a clinically meaningful effect on fedratinib pharmacokinetics.
Severe impairment (total bilirubin >3 times ULN and any AST): Avoid fedratinib use.
Hepatotoxicity during treatment:
ALT, AST, or bilirubin elevations (≥ grade 3): Interrupt fedratinib until resolved to ≤ grade 1 or baseline, then resume with the dose reduced by 100 mg/day below the prior fedratinib dose. Monitor ALT, AST, and bilirubin (total and direct) more frequently following the dose reduction. If ≥ grade 3 elevations recur, discontinue fedratinib treatment.
Modify fedratinib dose for adverse reactions. Discontinue fedratinib if unable to tolerate 200 mg once daily.
Hematologic toxicities: Consider dose reduction for patients who become transfusion dependent during fedratinib therapy.
Anemia: May require RBC transfusion; consider dose reduction in patients who become RBC transfusion dependent. May require permanent discontinuation.
Neutropenia (grade 4): Interrupt fedratinib until resolved to ≤ grade 2 or baseline, then resume with the dose reduced by 100 mg/day below the prior fedratinib dose.
Thrombocytopenia (grade 3 with active bleeding or grade 4): Interrupt fedratinib until resolved to ≤ grade 2 or baseline, then resume with the dose reduced by 100 mg/day below the prior fedratinib dose. May require platelet transfusion and/or permanent discontinuation of fedratinib for thrombocytopenia and bleeding requiring clinical intervention.
Nonhematologic toxicities:
GI toxicity (≥ grade 3 nausea, vomiting, or diarrhea not responding to supportive measures within 48 hours): Interrupt fedratinib until resolved to ≤ grade 1 or baseline, then resume with the dose reduced by 100 mg/day below the prior fedratinib dose.
Diarrhea: Promptly manage diarrhea with antidiarrheal medications at the first onset of symptoms.
Amylase or lipase elevations (≥ grade 3): Interrupt fedratinib until resolved to ≤ grade 1 or baseline, then resume with the dose reduced by 100 mg/day below the prior fedratinib dose.
Wernicke encephalopathy: If encephalopathy is suspected, immediately discontinue fedratinib and initiate parenteral thiamine; monitor until symptoms resolve or improve and thiamine levels normalize.
Other toxicities (≥ grade 3): Interrupt fedratinib until resolved to ≤ grade 1 or baseline, then resume with the dose reduced by 100 mg/day below the prior fedratinib dose.
Refer to adult dosing.
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified. Adverse reactions reported in adults.
>10%:
Endocrine & metabolic: Hyponatremia (26%), vitamin B deficiency (thiamine <70 nmol/L: 21%)
Gastrointestinal: Diarrhea (66%; grades ≥3: 5%), increased serum amylase (24%), increased serum lipase (35%), nausea (62%), vomiting (39%; grades ≥3: 3%)
Hematologic & oncologic: Anemia (40% to 74%; grades ≥3: 30% to 34%), neutropenia (23%; grades ≥3: 5%), thrombocytopenia (47%; grades ≥3: 12%)
Hepatic: Increased serum alanine aminotransferase (9% to 43%), increased serum aspartate aminotransferase (5% to 40%)
Nervous system: Asthenia (≤19%), fatigue (≤19%)
Neuromuscular & skeletal: Muscle spasm (12%)
Renal: Increased serum creatinine (10% to 59%)
1% to 10%:
Cardiovascular: Cardiogenic shock (1%), heart failure (5%), hypertension (4%)
Endocrine & metabolic: Weight gain (9%)
Genitourinary: Dysuria (6%), urinary tract infection (6%)
Nervous system: Dizziness (8%), headache (9%)
Neuromuscular & skeletal: Limb pain (10%), ostealgia (8%)
Frequency not defined:
Cardiovascular: Ischemic heart disease
Nervous system: Encephalopathy (including Wernicke's)
There are no contraindications listed in the manufacturer's US labeling.
Canadian labeling: Additional contraindications (not in US labeling): Hypersensitivity to fedratinib or any component of the formulation.
Concerns related to adverse effects:
• Cardiac effects: The risk for major adverse cardiovascular events, including cardiovascular death, myocardial infarction, and stroke, was increased with use of another Janus kinase (JAK)-inhibitor (as compared to tumor necrosis factor [TNF] blockers) in patients treated for rheumatoid arthritis (not an approved indication for fedratinib). Inform patients of the symptoms of serious cardiovascular events.
• Encephalopathy:Wernicke encephalopathy results from thiamine deficiency. Signs/symptoms of Wernicke encephalopathy may include ataxia, mental status changes, and ophthalmoplegia (eg, nystagmus, diplopia). Any change in mental status, confusion, or memory impairment should raise concern for potential encephalopathy (including Wernicke) and prompt a full evaluation, including a neurologic examination, assessment of thiamine levels, and imaging.
• GI toxicity: GI toxicities, including diarrhea, nausea, and vomiting, commonly occur with fedratinib. Grade 3 diarrhea and vomiting have occurred. The median time to onset (for any grade) of nausea, vomiting, and diarrhea was 1 day, with most events occurring within 2 weeks of treatment. Promptly manage diarrhea with antidiarrheal medications at the first onset of symptoms. For grade 3 or higher nausea, vomiting, or diarrhea that is not responsive within 48 hours to supportive measures, interrupt fedratinib until resolved to grade 0 or 1 or to baseline; then reinitiate fedratinib at a reduced dose. Monitor thiamine levels and replete as needed. Grade 3 or higher amylase and/or lipase elevations have developed with fedratinib. The median time to onset (for any grade) of amylase or lipase elevation was 15 days, with most cases occurring within 1 month of starting fedratinib treatment. Pancreatitis has been observed (rare) and resolved with fedratinib discontinuation. Monitor amylase and lipase at baseline, periodically during treatment, and as clinically indicated. For grade 3 or higher amylase and/or lipase elevations, interrupt fedratinib until resolved to grade 0 or 1 or to baseline; then reinitiate fedratinib at a reduced dose.
• Hematologic toxicity: Anemia, thrombocytopenia, and neutropenia may occur with fedratinib. New or worsening grade 3 anemia occurred in approximately one-third of patients. The median time to onset of grade 3 anemia (first event) was ~2 months, with most cases occurring within 3 months. Mean hemoglobin levels reached nadir after 12 to 16 weeks, with partial recovery and stabilization after 16 weeks. Approximately half of patients received RBC transfusions. Fedratinib was permanently discontinued due to anemia in a small percentage of patients. Consider dose reduction in patients who become RBC transfusion dependent. New or worsening ≥ grade 3 thrombocytopenia has been reported with fedratinib. The median time to onset of grade 3 thrombocytopenia (first event) was ~1 month, with most cases occurring within 4 months. A small percentage of patients received platelet transfusions and/or required permanent discontinuation due to thrombocytopenia and bleeding requiring clinical intervention. Obtain a CBC at baseline, periodically during treatment, and as clinically indicated. For grade 3 thrombocytopenia with active bleeding or grade 4 thrombocytopenia, interrupt fedratinib treatment until resolved to ≤ grade 2 or baseline; then reinitiate fedratinib with a reduced dose and monitor platelets as clinically indicated.
• Hepatotoxicity: ALT and AST elevations (all grades) occurred commonly with fedratinib treatment; grade 3 events have been reported (rare). The median time to onset of transaminase elevation (any grade) was ~1 month, with most cases occurring within 3 months. Monitor hepatic function at baseline, periodically during treatment, and as clinically indicated. For ≥ grade 3 ALT and/or AST elevations (>5 times ULN), interrupt fedratinib treatment until resolved to grade 0 or 1 or to baseline; then resume at a reduced dose. Discontinue fedratinib treatment for recurrence of ≥ grade 3 ALT or AST elevations. Avoid fedratinib use in patients with baseline severe hepatic impairment.
• Secondary malignancy: The risk for lymphoma and other malignancies (excluding nonmelanoma skin cancer) was increased with use of another JAK-inhibitor (as compared to TNF blockers) in patients treated for rheumatoid arthritis (not an approved indication for fedratinib). Patients who are current or past smokers are at additional increased risk.
• Thrombosis: The risk for thrombosis, including deep venous thrombosis, pulmonary embolism, and arterial thrombosis, has increased with use of another JAK-inhibitor (as compared to TNF blockers) in patients treated for rheumatoid arthritis (not an approved indication for fedratinib).
Disease-related concerns:
• Renal impairment: Dose reduction recommended in patients with severe renal impairment (CrCl <30 mL/minute).
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Capsule, Oral, as hydrochloride:
Inrebic: 100 mg
No
Capsules (Inrebic Oral)
100 mg (per each): $276.00
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Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Capsule, Oral, as hydrochloride:
Inrebic: 100 mg
Fedratinib is available through select specialty pharmacies and authorized distributors; access information is available at https://www.inrebicpro.com/resources-access.
Oral: May administer with or without food; administration with a high-fat meal may reduce the incidence of nausea and vomiting.
Fedratinib is associated with a moderate or high emetic potential; antiemetics may be recommended to prevent nausea and vomiting (Ref).
This medication is not on the NIOSH (2024) list; however, it may meet the criteria for a hazardous drug. Fedratinib may cause teratogenicity.
Use appropriate precautions for receiving, handling, storage, preparation, dispensing, transporting, administration, and disposal. Follow NIOSH and USP 800 recommendations and institution-specific policies/procedures for appropriate containment strategy (NIOSH 2023; NIOSH 2024; USP-NF 2020).
Note: Facilities may perform risk assessment of some hazardous drugs to determine if appropriate for alternative handling and containment strategies (USP-NF 2020). Refer to institution-specific handling policies/procedures.
An FDA-approved patient medication guide, which is available with the product information and at https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/212327s006lbl.pdf#page=211, must be dispensed with this medication.
Myelofibrosis: Treatment of intermediate-2 or high-risk primary or secondary (post polycythemia vera or post-essential thrombocythemia) myelofibrosis in adults.
Fedratinib may be confused with baricitinib, afatinib, dasatinib, entrectinib, gilteritinib, ruxolitinib, tofacitinib, upadacitinib.
Inrebic may be confused with Inlyta
The Institute for Safe Medication Practices (ISMP) includes this medication among its list of drug classes (chemotherapeutic agent, parenteral and oral) which have a heightened risk of causing significant patient harm when used in error (High-Alert Medications in Acute Care, Community/Ambulatory Care, and Long-Term Care Settings).
Substrate of CYP2C19 (Minor), CYP3A4 (Major), OATP1B1/1B3; Note: Assignment of Major/Minor substrate status based on clinically relevant drug interaction potential; Inhibits CYP2C19 (Moderate), CYP2D6 (Weak), CYP3A4 (Moderate);
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
5-Aminosalicylic Acid Derivatives: May increase myelosuppressive effects of Myelosuppressive Agents. Risk C: Monitor
Abemaciclib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Abemaciclib. Management: Monitor for increased abemaciclib toxicities if combined with moderate CYP3A4 inhibitors. Consider reducing the abemaciclib dose in 50 mg decrements if necessary. Risk C: Monitor
Abrocitinib: CYP2C19 Inhibitors (Moderate) may increase serum concentration of Abrocitinib. Risk C: Monitor
Acalabrutinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Acalabrutinib. Management: Reduce acalabrutinib dose to 100 mg once daily with concurrent use of a moderate CYP3A4 inhibitor. Monitor patient closely for both acalabrutinib response and evidence of adverse effects with any concurrent use. Risk D: Consider Therapy Modification
Acrivastine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Acrivastine. Risk C: Monitor
ALfentanil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of ALfentanil. Management: If use of alfentanil and moderate CYP3A4 inhibitors is necessary, consider dosage reduction of alfentanil until stable drug effects are achieved. Frequently monitor patients for respiratory depression and sedation when these agents are combined. Risk D: Consider Therapy Modification
Alfuzosin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Alfuzosin. Risk C: Monitor
Alitretinoin (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Alitretinoin (Systemic). Risk C: Monitor
ALPRAZolam: CYP3A4 Inhibitors (Moderate) may increase serum concentration of ALPRAZolam. Management: Consider alternatives to this combination when possible. If combined, consider an alprazolam dose reduction and monitor for increased alprazolam effects and toxicities (eg, sedation, lethargy). Risk D: Consider Therapy Modification
Amiodarone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Amiodarone. Risk C: Monitor
AmLODIPine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of AmLODIPine. Risk C: Monitor
Antithyroid Agents: Myelosuppressive Agents may increase neutropenic effects of Antithyroid Agents. Risk C: Monitor
Apixaban: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Apixaban. Risk C: Monitor
Aprepitant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Aprepitant. Risk X: Avoid
ARIPiprazole Lauroxil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of ARIPiprazole Lauroxil. Risk C: Monitor
ARIPiprazole: CYP3A4 Inhibitors (Moderate) may increase serum concentration of ARIPiprazole. Management: Monitor for increased aripiprazole pharmacologic effects. Aripiprazole dose adjustments may or may not be required based on concomitant therapy, indication, or dosage form. Consult full interaction monograph for specific recommendations. Risk C: Monitor
Atogepant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Atogepant. Risk C: Monitor
Atorvastatin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Atorvastatin. Risk C: Monitor
Avacopan: May increase serum concentration of Fedratinib. Fedratinib may increase serum concentration of Avacopan. Risk C: Monitor
Avanafil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Avanafil. Management: The maximum avanafil dose is 50 mg per 24-hour period when used together with a moderate CYP3A4 inhibitor. Patients receiving such a combination should also be monitored more closely for evidence of adverse effects (eg, hypotension, syncope, priapism). Risk D: Consider Therapy Modification
Avapritinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Avapritinib. Management: Avoid use of moderate CYP3A4 inhibitors with avapritinib. If this combination cannot be avoided, reduce the avapritinib dose to 100 mg daily for the treatment of GIST or to 50 mg daily for the treatment of advanced systemic mastocytosis. Risk D: Consider Therapy Modification
Axitinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Axitinib. Risk C: Monitor
Barnidipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Barnidipine. Risk C: Monitor
BCG (Intravesical): Myelosuppressive Agents may decrease therapeutic effects of BCG (Intravesical). Myelosuppressive Agents may increase adverse/toxic effects of BCG (Intravesical). Risk X: Avoid
Bedaquiline: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Bedaquiline. CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Bedaquiline. Risk C: Monitor
Belzutifan: CYP2C19 Inhibitors (Moderate) may increase serum concentration of Belzutifan. Risk C: Monitor
Benidipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Benidipine. Risk C: Monitor
Benzhydrocodone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Benzhydrocodone. Specifically, the concentration of hydrocodone may be increased. Risk C: Monitor
Blonanserin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Blonanserin. Risk C: Monitor
Bortezomib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Bortezomib. Risk C: Monitor
Bosutinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Bosutinib. Risk X: Avoid
Brexpiprazole: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Brexpiprazole. Management: The brexpiprazole dose should be reduced to 25% of usual if used together with both a moderate CYP3A4 inhibitor and a strong or moderate CYP2D6 inhibitor, or if a moderate CYP3A4 inhibitor is used in a CYP2D6 poor metabolizer. Risk C: Monitor
Brigatinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Brigatinib. Management: Avoid concurrent use of brigatinib with moderate CYP3A4 inhibitors when possible. If such a combination cannot be avoided, reduce the dose of brigatinib by approximately 40% (ie, from 180 mg to 120 mg, from 120 mg to 90 mg, or from 90 mg to 60 mg). Risk D: Consider Therapy Modification
Brivaracetam: CYP2C19 Inhibitors (Moderate) may increase serum concentration of Brivaracetam. Risk C: Monitor
Bromocriptine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Bromocriptine. Management: The bromocriptine dose should not exceed 1.6 mg daily with use of a moderate CYP3A4 inhibitor. The Cycloset brand specifically recommends this dose limitation, but other bromocriptine products do not make such specific recommendations. Risk D: Consider Therapy Modification
Budesonide (Oral Inhalation): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Budesonide (Oral Inhalation). Risk C: Monitor
Budesonide (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Budesonide (Systemic). Management: Avoid the concomitant use of CYP3A4 inhibitors and oral budesonide. If patients receive both budesonide and CYP3A4 inhibitors, they should be closely monitored for signs and symptoms of corticosteroid excess. Risk D: Consider Therapy Modification
Budesonide (Topical): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Budesonide (Topical). Risk X: Avoid
Buprenorphine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Buprenorphine. Risk C: Monitor
BusPIRone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of BusPIRone. Risk C: Monitor
Cabozantinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Cabozantinib. Risk C: Monitor
Cannabis: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Cannabis. More specifically, tetrahydrocannabinol and cannabidiol serum concentrations may be increased. Risk C: Monitor
Capivasertib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Capivasertib. Management: If capivasertib is combined with moderate CYP3A4 inhibitors, reduce the capivasertib dose to 320 mg twice daily for 4 days, followed by 3 days off. Monitor patients closely for adverse reactions. Risk D: Consider Therapy Modification
Cariprazine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Cariprazine. CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Cariprazine. Management: Cariprazine dose adjustments are recommended and depend upon whether a patient is initiating a moderate CYP3A4 inhibitor or cariprazine, as well as cariprazine indication. See full mono for details. Some non-US labels contraindicate this combination. Risk D: Consider Therapy Modification
Carisoprodol: CYP2C19 Inhibitors (Moderate) may decrease active metabolite exposure of Carisoprodol. CYP2C19 Inhibitors (Moderate) may increase serum concentration of Carisoprodol. Risk C: Monitor
Chloramphenicol (Ophthalmic): May increase adverse/toxic effects of Myelosuppressive Agents. Risk C: Monitor
Chloramphenicol (Systemic): Myelosuppressive Agents may increase myelosuppressive effects of Chloramphenicol (Systemic). Risk X: Avoid
Cilostazol: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Cilostazol. Management: Decrease the dose of cilostazol to 50 mg twice daily when combined with moderate CYP3A4 inhibitors. Risk D: Consider Therapy Modification
Cisapride: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Cisapride. Management: Consider alternatives to this combination. Prescribing information for some moderate CYP3A4 inhibitors state coadministration with cisapride is contraindicated, while some others recommend monitoring and dose titration. Risk D: Consider Therapy Modification
Citalopram: CYP2C19 Inhibitors (Moderate) may increase serum concentration of Citalopram. Management: Limit citalopram dose to a maximum of 20 mg/day if used with a moderate CYP2C19 inhibitor. Patients using this combination should be monitored closely for evidence of citalopram toxicity (eg, serotonin syndrome, QT prolongation). Risk D: Consider Therapy Modification
Cladribine: May increase myelosuppressive effects of Myelosuppressive Agents. Risk X: Avoid
Clindamycin (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Clindamycin (Systemic). Risk C: Monitor
CloBAZam: CYP2C19 Inhibitors (Moderate) may increase active metabolite exposure of CloBAZam. CYP2C19 Inhibitors (Moderate) may increase serum concentration of CloBAZam. Risk C: Monitor
Clofazimine: May increase serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Risk C: Monitor
Clopidogrel: CYP2C19 Inhibitors (Moderate) may decrease active metabolite exposure of Clopidogrel. Risk C: Monitor
CloZAPine: Myelosuppressive Agents may increase adverse/toxic effects of CloZAPine. Specifically, the risk for neutropenia may be increased. Risk C: Monitor
Cobimetinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Cobimetinib. Management: Avoid this combination when possible. If concurrent short term (14 days or less) use cannot be avoided, reduce the cobimetinib dose from 60 mg to 20 mg daily. Avoid concomitant use in patients already receiving reduced cobimetinib doses. Risk D: Consider Therapy Modification
Codeine: CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Codeine. Risk C: Monitor
Colchicine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Colchicine. Management: Avoidance, dose reduction, or increased monitoring for colchicine toxicity may be needed and will depend on brand, indication for colchicine use, renal/hepatic function, and use of a P-gp inhibitor. See full monograph for details. Risk D: Consider Therapy Modification
Conivaptan: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Conivaptan. Risk C: Monitor
Copanlisib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Copanlisib. Risk C: Monitor
Crizotinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Crizotinib. Risk C: Monitor
CycloSPORINE (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of CycloSPORINE (Systemic). Risk C: Monitor
CYP3A4 Inducers (Moderate): May decrease serum concentration of Fedratinib. Risk X: Avoid
CYP3A4 Inducers (Strong): May decrease serum concentration of Fedratinib. Risk X: Avoid
CYP3A4 Inhibitors (Moderate): May increase serum concentration of Fedratinib. Risk C: Monitor
CYP3A4 Inhibitors (Strong): May increase serum concentration of Fedratinib. Management: Consider alternatives when possible. If used together, decrease fedratinib dose to 200 mg/day. After the inhibitor is stopped, increase fedratinib to 300 mg/day for the first 2 weeks and then to 400 mg/day as tolerated. Risk D: Consider Therapy Modification
Dapoxetine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Dapoxetine. Management: The dose of dapoxetine should be limited to 30 mg per day when used together with a moderate inhibitor of CYP3A4. Risk D: Consider Therapy Modification
Daridorexant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Daridorexant. Management: Limit the daridorexant dose to 25 mg, no more than once per night, when combined with moderate CYP3A4 inhibitors. Risk D: Consider Therapy Modification
Darifenacin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Darifenacin. Risk C: Monitor
Dasatinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Dasatinib. Risk C: Monitor
Deferiprone: Myelosuppressive Agents may increase neutropenic effects of Deferiprone. Management: Avoid the concomitant use of deferiprone and myelosuppressive agents whenever possible. If this combination cannot be avoided, monitor the absolute neutrophil count more closely. Risk D: Consider Therapy Modification
Deflazacort: CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Deflazacort. Management: Administer one third of the recommended deflazacort dose when used together with a strong or moderate CYP3A4 inhibitor. Risk D: Consider Therapy Modification
Delamanid: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Delamanid. Risk C: Monitor
Desmopressin: Hyponatremia-Associated Agents may increase hyponatremic effects of Desmopressin. Risk C: Monitor
DexAMETHasone (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of DexAMETHasone (Systemic). Risk C: Monitor
Dexlansoprazole: CYP2C19 Inhibitors (Moderate) may increase serum concentration of Dexlansoprazole. Risk C: Monitor
DiazePAM: CYP2C19 Inhibitors (Moderate) may increase serum concentration of DiazePAM. Risk C: Monitor
Diazoxide Choline: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Diazoxide Choline. Risk C: Monitor
Dienogest: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Dienogest. Risk C: Monitor
DilTIAZem: CYP3A4 Inhibitors (Moderate) may increase serum concentration of DilTIAZem. Risk C: Monitor
Disopyramide: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Disopyramide. Risk C: Monitor
DOCEtaxel: CYP3A4 Inhibitors (Moderate) may increase serum concentration of DOCEtaxel. Risk C: Monitor
Dofetilide: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Dofetilide. Risk C: Monitor
Domperidone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Domperidone. Risk X: Avoid
DOXOrubicin (Conventional): CYP3A4 Inhibitors (Moderate) may increase serum concentration of DOXOrubicin (Conventional). Risk X: Avoid
DroNABinol: CYP3A4 Inhibitors (Moderate) may increase serum concentration of DroNABinol. Risk C: Monitor
Dronedarone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Dronedarone. Risk C: Monitor
Ebastine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ebastine. Risk C: Monitor
Elacestrant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Elacestrant. Risk X: Avoid
Elbasvir and Grazoprevir: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Elbasvir and Grazoprevir. Risk C: Monitor
Eletriptan: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Eletriptan. Risk X: Avoid
Elexacaftor, Tezacaftor, and Ivacaftor: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Elexacaftor, Tezacaftor, and Ivacaftor. Management: When combined with moderate CYP3A4 inhibitors, elexacaftor/tezacaftor/ivacaftor should be given in the morning, every other day. Ivacaftor alone should be given in the morning, every other day on alternate days. Risk D: Consider Therapy Modification
Eliglustat: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Eliglustat. Management: Reduce eliglustat dose to 84 mg daily in CYP2D6 EMs when used with moderate CYP3A4 inhibitors. Avoid use of moderate CYP3A4 inhibitors in CYP2D6 IMs or PMs. Use in CYP2D6 EMs or IMs also taking strong or moderate CYP2D6 inhibitors is contraindicated. Risk D: Consider Therapy Modification
Ensartinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ensartinib. Risk X: Avoid
Entrectinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Entrectinib. Management: Avoid moderate CYP3A4 inhibitors if possible. If needed, reduce entrectinib dose to 50 mg/day if starting dose 200 mg; to 100 mg/day if starting dose 300 mg; to 200 mg if starting dose 400 mg or 600 mg. Risk D: Consider Therapy Modification
Eplerenone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Eplerenone. Management: If coadministered with moderate CYP3A4 inhibitors, the max dose of eplerenone is 25 mg daily if used for heart failure; if used for hypertension initiate eplerenone 25 mg daily, titrate to max 25 mg twice daily. Risk D: Consider Therapy Modification
Ergot Derivatives (Vasoconstrictive CYP3A4 Substrates): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ergot Derivatives (Vasoconstrictive CYP3A4 Substrates). Risk C: Monitor
Erlotinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Erlotinib. Risk C: Monitor
Erythromycin (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Erythromycin (Systemic). Risk C: Monitor
Escitalopram: CYP2C19 Inhibitors (Moderate) may increase serum concentration of Escitalopram. Risk C: Monitor
Eszopiclone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Eszopiclone. Risk C: Monitor
Everolimus: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Everolimus. Risk C: Monitor
Felodipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Felodipine. Risk C: Monitor
FentaNYL: CYP3A4 Inhibitors (Moderate) may increase serum concentration of FentaNYL. Management: Consider fentanyl dose reductions when combined with a moderate CYP3A4 inhibitor. Monitor for respiratory depression and sedation. Upon discontinuation of a CYP3A4 inhibitor, consider a fentanyl dose increase; monitor for signs and symptoms of withdrawal. Risk D: Consider Therapy Modification
Finerenone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Finerenone. Risk C: Monitor
Flibanserin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Flibanserin. Management: Use of flibanserin with moderate CYP3A4 inhibitors is contraindicated. If starting flibanserin, start 2 weeks after the last dose of the CYP3A4 inhibitor. If starting a CYP3A4 inhibitor, start 2 days after the last dose of flibanserin. Risk X: Avoid
Fluconazole: May increase serum concentration of Fedratinib. Risk C: Monitor
Fluticasone (Nasal): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Fluticasone (Nasal). Risk C: Monitor
Fluticasone (Oral Inhalation): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Fluticasone (Oral Inhalation). Risk C: Monitor
Fosamprenavir: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Fosamprenavir. Risk C: Monitor
Fosaprepitant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Fosaprepitant. Risk X: Avoid
Fosphenytoin-Phenytoin: Fedratinib may increase serum concentration of Fosphenytoin-Phenytoin. Fosphenytoin-Phenytoin may decrease serum concentration of Fedratinib. Risk X: Avoid
Fusidic Acid (Systemic): May increase serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Management: Consider avoiding this combination if possible. If required, monitor patients closely for increased adverse effects of the CYP3A4 substrate. Risk D: Consider Therapy Modification
Gepirone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Gepirone. Management: Reduce the gepirone dose by 50% if combined with moderate CYP3A4 inhibitors. Monitor for QTc interval prolongation with combined use. Risk D: Consider Therapy Modification
Gepotidacin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Gepotidacin. Risk C: Monitor
Gilteritinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Gilteritinib. Risk C: Monitor
Glasdegib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Glasdegib. Risk C: Monitor
Grapefruit Juice: May increase serum concentration of Fedratinib. Risk C: Monitor
GuanFACINE: CYP3A4 Inhibitors (Moderate) may increase serum concentration of GuanFACINE. Management: Reduce the extended-release guanfacine dose 50% when combined with a moderate CYP3A4 inhibitor. Monitor for increased guanfacine toxicities when these agents are combined. Risk D: Consider Therapy Modification
Halofantrine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Halofantrine. Risk C: Monitor
HYDROcodone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of HYDROcodone. Risk C: Monitor
Ibrutinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ibrutinib. Management: When treating B-cell malignancies, decrease ibrutinib to 280 mg daily when combined with moderate CYP3A4 inhibitors. When treating graft versus host disease, monitor patients closely and reduce the ibrutinib dose as needed based on adverse reactions. Risk D: Consider Therapy Modification
Ifosfamide: CYP3A4 Inhibitors (Moderate) may increase adverse/toxic effects of Ifosfamide. CYP3A4 Inhibitors (Moderate) may decrease active metabolite exposure of Ifosfamide. Risk C: Monitor
Iloperidone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Iloperidone. Risk C: Monitor
Irinotecan Products: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Irinotecan Products. CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Irinotecan Products. Specifically, the serum concentration of SN-38 may be increased. Risk C: Monitor
Isavuconazonium Sulfate: Fedratinib may increase serum concentration of Isavuconazonium Sulfate. Isavuconazonium Sulfate may increase serum concentration of Fedratinib. Risk C: Monitor
Isradipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Isradipine. Risk C: Monitor
Ivabradine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ivabradine. Risk X: Avoid
Ivacaftor: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ivacaftor. Management: Ivacaftor dose reductions may be required; consult full drug interaction monograph content for age- and weight-specific dosage recommendations. Risk D: Consider Therapy Modification
Ivosidenib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ivosidenib. Management: Avoid use of moderate CYP3A4 inhibitors with ivosidenib whenever possible. If combined, monitor for increased ivosidenib toxicities, including QTc prolongation. Risk D: Consider Therapy Modification
Ixabepilone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ixabepilone. Risk C: Monitor
Lansoprazole: CYP2C19 Inhibitors (Moderate) may increase serum concentration of Lansoprazole. Risk C: Monitor
Lapatinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lapatinib. Risk C: Monitor
Larotrectinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Larotrectinib. Risk C: Monitor
Lefamulin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lefamulin. Management: Monitor for lefamulin adverse effects during coadministration of lefamulin tablets with moderate CYP3A4 inhibitors. Risk C: Monitor
Lemborexant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lemborexant. Risk X: Avoid
Leniolisib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Leniolisib. Risk C: Monitor
Lercanidipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lercanidipine. Risk C: Monitor
Levamlodipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Levamlodipine. Risk C: Monitor
Levomethadone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Levomethadone. Risk C: Monitor
Levomilnacipran: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Levomilnacipran. Risk C: Monitor
Lidocaine (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lidocaine (Systemic). CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Lidocaine (Systemic). Specifically, concentrations of monoethylglycinexylidide (MEGX) may be increased. Risk C: Monitor
Linezolid: May increase myelosuppressive effects of Myelosuppressive Agents. Risk C: Monitor
Lomitapide: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lomitapide. Risk X: Avoid
Lonafarnib: May increase serum concentration of Fedratinib. Management: Avoid this combination if possible. If required, reduce fedratinib to 200 mg/day. Increase to 300 mg/day for 2 weeks after lonafarnib is discontinued, and 400 mg/day thereafter as tolerated. Monitor for lonafarnib toxicities. Risk D: Consider Therapy Modification
Lovastatin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lovastatin. Risk C: Monitor
Lumateperone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lumateperone. Management: Limit the lumateperone dose to 21 mg once daily when used with a moderate CYP3A4 inhibitor. Risk D: Consider Therapy Modification
Lurasidone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lurasidone. Management: Reduce the lurasidone dose by half when initiating therapy with a moderate CYP3A4 inhibitor. If initiating lurasidone in a patient already receiving a moderate CYP3A4 inhibitor, start lurasidone at 20 mg/day with a max dose of 80 mg/day. Risk D: Consider Therapy Modification
Lurbinectedin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Lurbinectedin. Management: Avoid concomitant use of lurbinectedin and moderate CYP3A4 inhibitors when possible. If combined, reduce the lurbinectedin dose by 50%. Risk D: Consider Therapy Modification
Macitentan: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Macitentan. Risk C: Monitor
Manidipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Manidipine. Risk C: Monitor
Maraviroc: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Maraviroc. Risk C: Monitor
MATE1/2-K Substrates (Clinically Relevant with Inhibitors): Fedratinib may increase serum concentration of MATE1/2-K Substrates (Clinically Relevant with Inhibitors). Risk C: Monitor
Mavacamten: CYP2C19 Inhibitors (Moderate) may increase serum concentration of Mavacamten. Management: For patients on stable therapy with a moderate CYP2C19 inhibitor initiate mavacamten at 2.5 mg daily. For patients initiating a moderate CYP2C19 inhibitor during mavacamten therapy, dose reductions are recommended. See full mono for details. Risk D: Consider Therapy Modification
Mavacamten: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Mavacamten. Management: Start mavacamten at 5 mg/day if stable on a moderate CYP3A4 inhibitor, and reduce the mavacamten dose by one dose level if initiating a moderate CYP3A4 inhibitor. Avoid initiating moderate CYP3A4 inhibitors in patients on mavacamten 2.5 mg/day. Risk D: Consider Therapy Modification
Mavorixafor: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Mavorixafor. Risk C: Monitor
Meperidine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Meperidine. Risk C: Monitor
Methadone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Methadone. Management: If coadministration with moderate CYP3A4 inhibitors is necessary, consider methadone dose reductions until stable effects are achieved. Monitor patients closely for respiratory depression and sedation. Risk D: Consider Therapy Modification
MethylPREDNISolone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of MethylPREDNISolone. Risk C: Monitor
Methysergide: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Methysergide. Risk X: Avoid
Midazolam: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Midazolam. Management: Avoid concomitant use of nasal midazolam and moderate CYP3A4 inhibitors. Consider alternatives to use with oral midazolam whenever possible and consider using lower midazolam doses. Monitor patients for sedation and respiratory depression if combined. Risk D: Consider Therapy Modification
Midostaurin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Midostaurin. Risk C: Monitor
Mirodenafil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Mirodenafil. Risk C: Monitor
Mobocertinib: CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Mobocertinib. CYP3A4 Inhibitors (Moderate) may increase serum concentration of Mobocertinib. Management: Avoid use of moderate CYP3A4 inhibitors with mobocertinib when possible. If combined, the mobocertinib dose should be reduced by approximately 50% (ie, from 160 mg to 80 mg, 120 mg to 40 mg, or 80 mg to 40 mg). Monitor QTc interval closely. Risk D: Consider Therapy Modification
Moclobemide: CYP2C19 Inhibitors (Moderate) may increase serum concentration of Moclobemide. Risk C: Monitor
Naldemedine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Naldemedine. Risk C: Monitor
Nalfurafine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Nalfurafine. Risk C: Monitor
Naloxegol: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Naloxegol. Management: The use of naloxegol and moderate CYP3A4 inhibitors should be avoided. If concurrent use is unavoidable, reduce naloxegol dose to 12.5 mg once daily and monitor for signs of opiate withdrawal (eg, hyperhidrosis, chills, diarrhea, anxiety, irritability). Risk D: Consider Therapy Modification
Neratinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Neratinib. Risk C: Monitor
NIFEdipine (Topical): CYP3A4 Inhibitors (Moderate) may increase serum concentration of NIFEdipine (Topical). Risk C: Monitor
NIFEdipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of NIFEdipine. Risk C: Monitor
NiMODipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of NiMODipine. Risk C: Monitor
Nirogacestat: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Nirogacestat. Risk X: Avoid
Nisoldipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Nisoldipine. Risk X: Avoid
Nitrendipine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Nitrendipine. Risk C: Monitor
OCT2 Substrates (Clinically Relevant with Inhibitors): Fedratinib may increase serum concentration of OCT2 Substrates (Clinically Relevant with Inhibitors). Risk C: Monitor
Olaparib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Olaparib. Management: Avoid use of moderate CYP3A4 inhibitors with olaparib, if possible. If such concurrent use cannot be avoided, the dose of olaparib tablets should be reduced to 150 mg twice daily and the dose of olaparib capsules should be reduced to 200 mg twice daily. Risk D: Consider Therapy Modification
Oliceridine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Oliceridine. Risk C: Monitor
Olmutinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Olmutinib. Risk C: Monitor
Omaveloxolone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Omaveloxolone. Management: Avoid this combination if possible. If coadministration is required, decrease the omaveloxolone dose to 100 mg daily and monitor closely for adverse reactions. If adverse reactions occur, decrease omaveloxolone to 50 mg daily. Risk D: Consider Therapy Modification
Omeprazole: CYP2C19 Inhibitors (Moderate) may increase serum concentration of Omeprazole. Risk C: Monitor
OxyCODONE: CYP3A4 Inhibitors (Moderate) may increase serum concentration of OxyCODONE. Serum concentrations of the active metabolite Oxymorphone may also be increased. Risk C: Monitor
PACLitaxel (Conventional): CYP3A4 Inhibitors (Moderate) may increase serum concentration of PACLitaxel (Conventional). Risk C: Monitor
PACLitaxel (Protein Bound): CYP3A4 Inhibitors (Moderate) may increase serum concentration of PACLitaxel (Protein Bound). Risk C: Monitor
Palbociclib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Palbociclib. Risk C: Monitor
Palovarotene: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Palovarotene. Management: Avoid concomitant use of palovarotene and moderate CYP3A4 inhibitors when possible. If combined, decrease palovarotene dose by 50% as described in the full interaction monograph. Monitor for palovarotene toxicities when combined. Risk D: Consider Therapy Modification
Panobinostat: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Panobinostat. Risk C: Monitor
PAZOPanib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of PAZOPanib. Risk C: Monitor
Pemigatinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Pemigatinib. Management: If combined use cannot be avoided, reduce the pemigatinib dose from 13.5 mg daily to 9 mg daily, or from 9 mg daily to 4.5 mg daily. Resume prior pemigatinib dose after stopping the moderate inhibitor once 3 half-lives of the inhibitor has passed. Risk D: Consider Therapy Modification
Pimavanserin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Pimavanserin. Risk C: Monitor
Pimecrolimus: CYP3A4 Inhibitors (Moderate) may decrease metabolism of Pimecrolimus. Risk C: Monitor
Pimozide: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Pimozide. Risk X: Avoid
Piperaquine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Piperaquine. Risk C: Monitor
Pirtobrutinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Pirtobrutinib. Risk C: Monitor
PONATinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of PONATinib. Risk C: Monitor
Pralsetinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Pralsetinib. Management: If this combo cannot be avoided, decrease pralsetinib dose from 400 mg daily to 300 mg daily; from 300 mg daily to 200 mg daily; and from 200 mg daily to 100 mg daily. Risk D: Consider Therapy Modification
Prazepam: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Prazepam. Risk C: Monitor
Praziquantel: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Praziquantel. Risk C: Monitor
Proguanil: CYP2C19 Inhibitors (Moderate) may increase serum concentration of Proguanil. CYP2C19 Inhibitors (Moderate) may decrease active metabolite exposure of Proguanil. Risk C: Monitor
Promazine: May increase myelosuppressive effects of Myelosuppressive Agents. Risk C: Monitor
QUEtiapine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of QUEtiapine. Risk C: Monitor
Quinidine (Non-Therapeutic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Quinidine (Non-Therapeutic). Risk C: Monitor
QuiNIDine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of QuiNIDine. Risk C: Monitor
QuiNINE: CYP3A4 Inhibitors (Moderate) may increase serum concentration of QuiNINE. Risk C: Monitor
Ranolazine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ranolazine. Management: Limit the ranolazine dose to a maximum of 500 mg twice daily in patients concurrently receiving moderate CYP3A4 inhibitors. Monitor for increased ranolazine effects and toxicities during concomitant use. Risk D: Consider Therapy Modification
Red Yeast Rice: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Red Yeast Rice. Risk C: Monitor
Regorafenib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Regorafenib. CYP3A4 Inhibitors (Moderate) may decrease active metabolite exposure of Regorafenib. Risk C: Monitor
Repotrectinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Repotrectinib. Risk X: Avoid
Ribociclib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ribociclib. Risk C: Monitor
Rimegepant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Rimegepant. Management: If taking rimegepant for the acute treatment of migraine, avoid a second dose of rimegepant within 48 hours when used concomitantly with moderate CYP3A4 inhibitors. No dose adjustment needed if using rimegepant for prevention of episodic migraine. Risk D: Consider Therapy Modification
Rivaroxaban: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Rivaroxaban. This warning is more specifically for drugs that are inhibitors of both CYP3A4 and P-glycoprotein. For erythromycin, refer to more specific erythromycin-rivaroxaban monograph recommendations. Risk C: Monitor
Roflumilast-Containing Products: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Roflumilast-Containing Products. Risk C: Monitor
Ropeginterferon Alfa-2b: Myelosuppressive Agents may increase myelosuppressive effects of Ropeginterferon Alfa-2b. Management: Avoid coadministration of ropeginterferon alfa-2b and other myelosuppressive agents. If this combination cannot be avoided, monitor patients for excessive myelosuppressive effects. Risk D: Consider Therapy Modification
Rupatadine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Rupatadine. Risk C: Monitor
Ruxolitinib (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ruxolitinib (Systemic). Risk C: Monitor
Salmeterol: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Salmeterol. Risk C: Monitor
SAXagliptin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of SAXagliptin. Risk C: Monitor
Selpercatinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Selpercatinib. Management: Avoid combination if possible. If use is necessary, reduce selpercatinib dose as follows: from 120 mg twice/day to 80 mg twice/day, or from 160 mg twice/day to 120 mg twice/day. Risk D: Consider Therapy Modification
Selumetinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Selumetinib. Management: Avoid concomitant use when possible. If combined, selumetinib dose reductions are recommended and vary based on body surface area and selumetinib dose. For details, see the full drug interaction monograph or selumetinib prescribing information. Risk D: Consider Therapy Modification
Sertindole: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Sertindole. Risk X: Avoid
Sildenafil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Sildenafil. Risk C: Monitor
Silodosin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Silodosin. Risk C: Monitor
Simeprevir: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Simeprevir. Risk X: Avoid
Simvastatin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Simvastatin. CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Simvastatin. Risk C: Monitor
Sirolimus (Conventional): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Sirolimus (Conventional). Management: Monitor for increased serum concentrations of sirolimus if combined with a moderate CYP3A4 inhibitor. Lower initial sirolimus doses or sirolimus dose reductions will likely be required. Risk D: Consider Therapy Modification
Sirolimus (Protein Bound): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Sirolimus (Protein Bound). Management: Reduce the dose of protein bound sirolimus to 56 mg/m2 when used concomitantly with a moderate CYP3A4 inhibitor. Risk D: Consider Therapy Modification
Solifenacin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Solifenacin. Risk C: Monitor
Sonidegib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Sonidegib. Management: Avoid concomitant use of sonidegib and moderate CYP3A4 inhibitors when possible. When concomitant use cannot be avoided, limit CYP3A4 inhibitor use to less than 14 days and monitor for sonidegib toxicity (particularly musculoskeletal adverse reactions). Risk D: Consider Therapy Modification
Sparsentan: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Sparsentan. Risk C: Monitor
SUFentanil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of SUFentanil. Risk C: Monitor
SUNItinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of SUNItinib. Risk C: Monitor
Suvorexant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Suvorexant. Management: The recommended dose of suvorexant is 5 mg daily in patients receiving a moderate CYP3A4 inhibitor. The dose can be increased to 10 mg daily (maximum dose) if necessary for efficacy. Risk D: Consider Therapy Modification
Suzetrigine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Suzetrigine. Management: Reduce suzetrigine dose as follows: initiate with 100 mg for 1 dose; then 12 hours after first dose, give 50 mg every 12 hours for doses 2, 3, and 4; then 50 mg every 24 hours for dose 5 and thereafter. Risk D: Consider Therapy Modification
Tacrolimus (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tacrolimus (Systemic). Risk C: Monitor
Tacrolimus (Topical): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tacrolimus (Topical). Risk C: Monitor
Tadalafil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tadalafil. Risk C: Monitor
Tamsulosin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tamsulosin. Risk C: Monitor
Tazemetostat: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tazemetostat. Management: Avoid when possible. If combined, reduce tazemetostat dose from 800 mg twice daily to 400 mg twice daily, from 600 mg twice daily to 400 mg in AM and 200 mg in PM, or from 400 mg twice daily to 200 mg twice daily. Risk D: Consider Therapy Modification
Temsirolimus: CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Temsirolimus. Specifically, concentrations of sirolimus may be increased. Risk C: Monitor
Tetrahydrocannabinol and Cannabidiol: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tetrahydrocannabinol and Cannabidiol. Risk C: Monitor
Tetrahydrocannabinol: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tetrahydrocannabinol. Risk C: Monitor
Tezacaftor and Ivacaftor: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tezacaftor and Ivacaftor. Management: If combined with moderate CYP3A4 inhibitors, give tezacaftor/ivacaftor in the morning, every other day; give ivacaftor in the morning, every other day on alternate days. Tezacaftor/ivacaftor dose depends on age and weight; see full Lexi-Interact monograph Risk D: Consider Therapy Modification
Thioridazine: CYP2D6 Inhibitors (Weak) may increase serum concentration of Thioridazine. Management: Consider avoiding concomitant use of thioridazine and weak CYP2D6 inhibitors. If combined, monitor closely for QTc interval prolongation and arrhythmias. Some weak CYP2D6 inhibitors list use with thioridazine as a contraindication. Risk D: Consider Therapy Modification
Thiotepa: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Thiotepa. CYP3A4 Inhibitors (Moderate) may decrease active metabolite exposure of Thiotepa. Risk C: Monitor
Ticagrelor: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ticagrelor. CYP3A4 Inhibitors (Moderate) may decrease active metabolite exposure of Ticagrelor. Risk C: Monitor
Tilidine: CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Tilidine. CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tilidine. Risk C: Monitor
Tofacitinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tofacitinib. Risk C: Monitor
Tolterodine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tolterodine. Risk C: Monitor
Tolvaptan: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tolvaptan. Management: Avoid this combination with Samsca brand of tolvaptan. Reduce dose for Jynarque brand: 90 mg AM and 30 mg PM, reduce to 45 mg AM and 15 mg PM; 60 mg AM and 30 mg PM, reduce to 30 mg AM and 15 mg PM; 45 mg AM and 15 mg PM, reduce to 15 mg AM and PM. Risk D: Consider Therapy Modification
Toremifene: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Toremifene. Risk C: Monitor
Trabectedin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Trabectedin. Risk C: Monitor
TraMADol: CYP3A4 Inhibitors (Moderate) may increase serum concentration of TraMADol. CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of TraMADol. Risk C: Monitor
TraZODone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of TraZODone. Risk C: Monitor
Tretinoin (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Tretinoin (Systemic). Risk C: Monitor
Triamcinolone (Systemic): CYP3A4 Inhibitors (Moderate) may increase serum concentration of Triamcinolone (Systemic). Risk C: Monitor
Triazolam: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Triazolam. Management: Consider triazolam dose reduction in patients receiving concomitant moderate CYP3A4 inhibitors. Risk D: Consider Therapy Modification
Ubrogepant: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Ubrogepant. Management: Use an initial ubrogepant dose of 50 mg and avoid a second dose for 24 hours when used with moderate CYP3A4 inhibitors. Risk D: Consider Therapy Modification
Udenafil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Udenafil. Risk C: Monitor
Valbenazine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Valbenazine. CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Valbenazine. Risk C: Monitor
Vamorolone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Vamorolone. Risk C: Monitor
Vanzacaftor, Tezacaftor, and Deutivacaftor: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Vanzacaftor, Tezacaftor, and Deutivacaftor. Management: Age- and weight-specific dose reductions of vanzacaftor, tezacaftor, and deutivacaftor are recommended. Please see full Interact monograph or labeling for details. Risk D: Consider Therapy Modification
Vardenafil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Vardenafil. Management: Limit Levitra (vardenafil) dose to a single 5 mg dose within a 24-hour period if combined with moderate CYP3A4 inhibitors. Avoid concomitant use of Staxyn (vardenafil) and moderate CYP3A4 inhibitors. Combined use is contraindicated outside of the US. Risk D: Consider Therapy Modification
Vemurafenib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Vemurafenib. Risk C: Monitor
Venetoclax: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Venetoclax. Management: Reduce the venetoclax dose by at least 50% in patients requiring concomitant treatment with moderate CYP3A4 inhibitors. Resume the previous venetoclax dose 2 to 3 days after discontinuation of moderate CYP3A4 inhibitors. Risk D: Consider Therapy Modification
Verapamil: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Verapamil. Risk C: Monitor
Vilazodone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Vilazodone. Risk C: Monitor
VinBLAStine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of VinBLAStine. Risk C: Monitor
VinCRIStine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of VinCRIStine. Risk C: Monitor
Vindesine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Vindesine. Risk C: Monitor
Vinflunine: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Vinflunine. CYP3A4 Inhibitors (Moderate) may increase active metabolite exposure of Vinflunine. Risk C: Monitor
Voclosporin: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Voclosporin. Management: Decrease the voclosporin dose to 15.8 mg in the morning and 7.9 mg in the evening when combined with moderate CYP3A4 inhibitors. Risk D: Consider Therapy Modification
Vorapaxar: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Vorapaxar. Risk C: Monitor
Zanubrutinib: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Zanubrutinib. Management: Decrease the zanubrutinib dose to 80 mg twice daily during coadministration with a moderate CYP3A4 inhibitor. Further dose adjustments may be required for zanubrutinib toxicities, refer to prescribing information for details. Risk D: Consider Therapy Modification
Zopiclone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Zopiclone. Risk C: Monitor
Zuranolone: CYP3A4 Inhibitors (Moderate) may increase serum concentration of Zuranolone. Risk C: Monitor
Based on a single 500 mg fedratinib dose, a low-fat, low-calorie (162 calories; 6% from fat, 78% from carbohydrate, 16% from protein) or a high-fat, high-calorie (815 calories; 52% from fat, 33% from carbohydrate, 15% from protein) meal increased AUCinf up to 24% and Cmax up to 14%.
Adverse events were observed in animal reproduction studies.
It is not known if fedratinib is present in breast milk.
Due to the potential for serious adverse reactions in the breastfed infant, breastfeeding is not recommended by the manufacturer during therapy and for at least ≥1 month after the last fedratinib dose.
Assess thiamine levels (in all patients) prior to fedratinib initiation and as clinically indicated. Monitor CBC (with platelets), hepatic function, amylase, lipase, and renal function (creatinine and BUN) at baseline, periodically during treatment, and as clinically indicated. Monitor for signs/symptoms of encephalopathy (if encephalopathy occurs, monitor until symptoms resolve or improve and thiamine levels normalize). Monitor for signs/symptoms of diarrhea, nausea/vomiting, and bleeding. Monitor for signs/symptoms of thrombosis and for major adverse cardiovascular events, particularly in patients who are current or past smokers and patients with other cardiovascular risk factors. Monitor for signs/symptoms of secondary malignancy. Monitor adherence.
Fedratinib is a kinase inhibitor with activity against both wild-type and mutated Janus-associated kinase 2 (JAK2) and FMS-like tyrosine kinase 3 (FLT3). Fedratinib is selective for JAK2, with higher inhibitory activity for JAK2 (versus JAK1, JAK3, and TYK2). Abnormal JAK2 activation is associated with myeloproliferative neoplasms, including myelofibrosis and polycythemia vera. Fedratinib reduces phosphorylation of signal transducer and activator of transcription (STAT3/5) proteins, inhibits cell proliferation, and induces apoptosis in mutated JAK2 and FLT3 cell lines, improving WBC counts, hematocrit, splenomegaly, and fibrosis.
Onset: STAT3 phosphorylation inhibition (maximal): ~2 hours
Duration: STAT3 phosphorylation inhibition: 24 hours
Distribution: Vd: 1,770 L
Protein binding: ≥92% to plasma proteins
Metabolism: Via CYP3A4, CYP2C19, and flavin-containing monooxygenase 3 (FMO3)
Half-life elimination: Effective: 41 hours; Terminal: ~114 hours
Time to peak: 3 hours (range: 2 to 4 hours)
Excretion: Feces (77%; 23% as unchanged drug); Urine (5%; 3% as unchanged drug); Clearance: 13 L/hour
Altered kidney function: Following a single 300 mg fedratinib dose, the AUCinf increased by 1.5-fold in subjects with moderate (CrCl 30 to 59 mL/minute) impairment and 1.9-fold in subjects with severe (CrCl 15 to 29 mL/minute) impairment, compared to that in subjects with CrCl ≥90 mL/minute).
