Encorafenib and Ondansetron: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ondansetron
No brand names on recordEncorafenib
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 risk of QT interval prolongation
Interaction Deep Dive
Encorafenib is associated with dose-dependent QTc interval prolongation. Avoid coadministration with other medicinal products known to prolong the QT/QTc interval. Monitor patients who already have or who are at significant risk of developing QTc prolongation, including patients with known long QT syndromes, clinically significant bradyarrhythmias, severe or uncontrolled heart failure and those taking other medicinal products associated with QT prolongation. Correct hypokalemia and hypomagnesemia prior to and during encorafenib administration. Withhold encorafenib until QTcF less than or equal to 500 ms, resume at reduced dose. If more than one recurrence, permanently discontinue encorafenib. Also, permanently discontinue encorafenib for QTcF more than 500 ms1.
Why it happens (mechanism)
Additive QT interval prolongation
Common questions
Can I take Encorafenib and Ondansetron together?
Increased risk of QT interval prolongation Always confirm with your pharmacist or prescriber before making any change.
How serious is the Encorafenib and Ondansetron 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 Encorafenib or Ondansetron 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: BRAFTOVI(R) oral capsules, encorafenib oral capsules. Array BioPharma Inc (per FDA), Boulder, CO, 2024. DailyMed
Keep reading about Ondansetron
Keep reading about Encorafenib
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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