Dofetilide and Fedratinib: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Fedratinib
Dofetilide
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased dofetilide exposure and an increased risk of dofetilide-related adverse events
Interaction Deep Dive
Coadministration of fedratinib with drugs that are CYP3A4 substrates and that are renally excreted by organic cation transporter (OCT2) and multidrug and toxin extrusion (MATE)1/2-K such as dofetilide can decrease the renal clearance of dofetilide. If coadministration is necessary, monitor for adverse reactions and consider dose modifications for drugs renally excreted by OCT2 or MATE1/2-K1.
Why it happens (mechanism)
Reduced renal clearance of dofetilide; inhibition of OCT2 or MATE1/2-K efflux transport of dofetilide by fedratinib; inhibition of CYP3A4-mediated metabolism of dofetilide
Literature reports
1 report — tap to read
a) Single-dose coadministration of fedratinib 600 mg and metformin 1000 mg (OCT2 and MATE1/2-K substrate) reduced the renal clearance of metformin by 36% 1.
Common questions
Can I take Dofetilide and Fedratinib together?
Increased dofetilide exposure and an increased risk of dofetilide-related adverse events Always confirm with your pharmacist or prescriber before making any change.
How serious is the Dofetilide and Fedratinib interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Dofetilide or Fedratinib need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: INREBIC(R) oral capsules, fedratinib oral capsules. Bristol-Myers Squibb Company (per FDA), Princeton, NJ, 2023. DailyMed
Keep reading about Fedratinib
Keep reading about Dofetilide
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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