Lansoprazole and Fedratinib: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Fedratinib
Lansoprazole
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 CYP2C19 substrate exposure
Interaction Deep Dive
Concomitant use of fedratinib (a CYP2C19 inhibitor) with CYP2C19 substrates may increase the substrate concentrations and the risk of adverse reactions of these substrates. In single-dose pharmacokinetic studies, fedratinib increased omeprazole (CYP2C19 substrate) AUC by 3-fold. If coadministration is necessary, monitor for adverse reactions and adjust the dose of drugs that are CYP2C19 substrates1.
Why it happens (mechanism)
Inhibition of CYP2C19-mediated substrate metabolism by fedratinib
Literature reports
1 report — tap to read
a) Coadministration of a single dose of omeprazole 20 mg (CYP2C19 substrate) with fedratinib increased omeprazole AUC by 3-fold 1.
Common questions
Can I take Lansoprazole and Fedratinib together?
Increased CYP2C19 substrate exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Lansoprazole 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 "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 Lansoprazole 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 Lansoprazole
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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