Nelfinavir and Avapritinib: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Nelfinavir
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
Increased avapritinib exposure and increased incidence and severity of adverse reactions
Interaction Deep Dive
Avoid concomitant administration of avapritinib with strong CYP3A inhibitors. Coadministration of avapritinib with a strong CYP3A inhibitor increases avapritinib exposure, which may increase the incidence and severity of adverse reactions of avapritinib. Coadministration of avapritinib with itraconazole (a strong CYP3A inhibitor) is predicted to increase avapritinib AUC by 600% at steady state1.
Why it happens (mechanism)
Inhibition of CYP3A-mediated metabolism of avapritinib
Literature reports
1 report — tap to read
a) Coadministration of avapritinib 300 mg once daily with itraconazole 200 mg once daily (a strong CYP3A inhibitor) is predicted to increase avapritinib AUC by 600% at steady state 1.
Common questions
Can I take Nelfinavir and Avapritinib together?
Increased avapritinib exposure and increased incidence and severity of adverse reactions Always confirm with your pharmacist or prescriber before making any change.
How serious is the Nelfinavir and Avapritinib 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 Nelfinavir or Avapritinib 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 Nelfinavir
Keep reading about Avapritinib
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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