Drug interactions
Donepezil + St john's wort
Severity: Moderate
Donepezil and St john's wort: 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
St John's wort induces CYP3A4 and may lower donepezil exposure, reducing its effect.
What this interaction means in plain words
Donepezil and St john's wort 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.
Why it happens
Induction of CYP3A4 (and possibly P-glycoprotein) increasing donepezil clearance.
What to do
Advise against using St John's wort with donepezil. If it is stopped, watch for rising donepezil effects.
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?
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Other interactions of Donepezil
- Donepezil + Dronedarone Contraindicated
- Donepezil + Pimozide Contraindicated
- Donepezil + Thioridazine Contraindicated
- Donepezil + Vandetanib Contraindicated
- Amiodarone + Donepezil Major
- Amisulpride + Donepezil Major
Frequently asked questions
Can I take Donepezil with St john's wort?
MediHelp rates the interaction as moderate. Donepezil and St john's wort 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. St John's wort induces CYP3A4 and may lower donepezil exposure, reducing its effect.
How serious is the interaction between Donepezil and St john's wort?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise against using St John's wort with donepezil. If it is stopped, watch for rising donepezil effects.
What other medicines interact with Donepezil?
MediHelp also lists interactions of Donepezil with, for example, Dronedarone, Pimozide, Thioridazine. The full list is on the Donepezil page.
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