Avapritinib and Telotristat Ethyl: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Telotristat Ethyl
Avapritinib
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
Reduced avapritinib exposure and reduced efficacy of avapritinib
Interaction Deep Dive
Avoid coadministration of avapritinib with strong or moderate CYP3A inducers. Coadministration of avapritinib with a strong or moderate CYP3A inducer may reduce avapritinib exposure, which may reduce efficacy of avapritinib1.
Why it happens (mechanism)
Induction of CYP3A-mediated metabolism of avapritinib
Literature reports
2 reports — tap to read
a) Coadministration of avapritinib 400 mg as a single dose with rifAMPin 600 mg once daily (a strong CYP3A inducer) decreased avapritinib Cmax by 74% and AUC by 92% 1.
b) Coadministration of avapritinib 300 mg once daily with efavirenz 600 mg once daily (a moderate CYP3A inducer) is predicted to decrease avapritinib Cmax by 55% and AUC by 62% at steady-state 1.
Common questions
Can I take Avapritinib and Telotristat Ethyl together?
Reduced avapritinib exposure and reduced efficacy of avapritinib Always confirm with your pharmacist or prescriber before making any change.
How serious is the Avapritinib and Telotristat Ethyl 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.
Questions for your pharmacist
- Does my dose of Avapritinib or Telotristat Ethyl 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: AYVAKIT(TM) oral tablets, avapritinib oral tablets. Blueprint Medicines Corporation (per manufacturer), Cambridge, MA, 2024. DailyMed
Keep reading about Telotristat Ethyl
Keep reading about Avapritinib
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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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