Clindamycin and Fedratinib: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 1, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Fedratinib
Clindamycin
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.
Let's talk about taking fedratinib (Inrebic) and clindamycin together. Your body uses a liver enzyme called CYP3A4 to break down clindamycin. Fedratinib slows that enzyme down. So clindamycin can build up higher than usual in your body, which may raise the chance of side effects like stomach upset, diarrhea, or nausea.
The good news is this is very manageable. Your doctor or pharmacist may keep a closer eye on you and adjust your clindamycin dose if needed. Please don't stop or change either medicine on your own. Just check in with your care team so they can tailor things for you.
Effect: Fedratinib inhibits CYP3A4, reducing clearance of CYP3A4 substrates and increasing their exposure. Clindamycin is partly metabolized by CYP3A4, so its concentrations may rise, increasing risk of adverse effects (GI intolerance, diarrhea).
- Direction: Increased clindamycin exposure (fedratinib is the inhibitor; clindamycin is the affected substrate, not a prodrug).
- Magnitude: Not established for clindamycin; fedratinib raised midazolam AUC ~4-fold.
- Evidence: Probable; severity major; onset unspecified.
- Management: If coadministration is necessary, monitor for adverse reactions and adjust the clindamycin dose as individualized by the care team.
What happens
Increased CYP3A4 substrate exposure
Interaction Deep Dive
When fedratinib, which inhibits CYP3A4, is taken alongside substrates of CYP3A4, the levels of those substrates can rise, elevating the likelihood of adverse reactions from them. Pharmacokinetic investigations using single doses showed that fedratinib raised the AUC of midazolam (a CYP3A4 substrate) by 4-fold. Should combined administration be required, watch for adverse reactions and modify the dosing of CYP3A4 substrate medications1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated substrate metabolism by fedratinib
How to manage this interaction
If your care team has you on both, here is how they typically handle it:
- Keep taking both as prescribed unless your prescriber tells you otherwise.
- Your team may monitor you more closely for clindamycin side effects such as nausea, stomach pain, or diarrhea.
- Your clindamycin dose may need to be adjusted and individualized by your care team while you are on fedratinib.
Tell your pharmacist or prescriber if you notice new or worsening stomach or bowel symptoms, especially significant or persistent diarrhea. A quick check-in lets them tailor your treatment safely.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) Administering a single 2 mg dose of midazolam (a CYP3A4 substrate) together with fedratinib produced a 4-fold rise in midazolam AUC 1.
Common questions
Can I take Clindamycin and Fedratinib together?
Fedratinib can slow the breakdown of clindamycin, raising its levels and the chance of side effects; keep taking both as prescribed but ask your care team about monitoring and possible dose adjustment. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Clindamycin 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 is the Clindamycin and Fedratinib interaction managed?
If your care team has you on both, here is how they typically handle it: Keep taking both as prescribed unless your prescriber tells you otherwise. Your team may monitor you more closely for clindamycin side effects such as nausea, stomach pain, or diarrhea. Your clindamycin dose may need to be adjusted and individualized by your care team while you are on fedratinib. Tell your pharmacist or presc… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Clindamycin 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 Clindamycin
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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