Drug interactions
Avapritinib + Diphenhydramine
Severity: Moderate
Avapritinib and Diphenhydramine: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Avapritinib can cause cognitive effects such as memory impairment, confusion and somnolence. Diphenhydramine may add to sedation and cognitive impairment.
What this interaction means in plain words
Avapritinib and Diphenhydramine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Avapritinib belongs to Oncology; Diphenhydramine belongs to Respiratory.
Why it happens
Additive CNS depressant and cognitive effects; no pharmacokinetic mechanism is established.
What to do
Monitor for worsening drowsiness and cognitive changes, and prefer a non-sedating antihistamine. Follow avapritinib label guidance if cognitive adverse reactions develop.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Avapritinib and Diphenhydramine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Diphenhydramine
Other interactions of Avapritinib
Frequently asked questions
Can I take Avapritinib with Diphenhydramine?
MediHelp rates the interaction as moderate. Avapritinib and Diphenhydramine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Avapritinib can cause cognitive effects such as memory impairment, confusion and somnolence. Diphenhydramine may add to sedation and cognitive impairment.
How serious is the interaction between Avapritinib and Diphenhydramine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for worsening drowsiness and cognitive changes, and prefer a non-sedating antihistamine. Follow avapritinib label guidance if cognitive adverse reactions develop.
What other medicines interact with Diphenhydramine?
MediHelp also lists interactions of Diphenhydramine with, for example, Alfentanil, Belladonna and opium, Benzhydrocodone / acetaminophen. The full list is on the Diphenhydramine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
