Drug interactions
Donepezil + Primidone
Severity: Moderate
Donepezil and Primidone: 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
Primidone is metabolized to phenobarbital, an inducer of CYP3A4, and may reduce donepezil exposure over time. Loss of therapeutic effect is possible.
What this interaction means in plain words
Donepezil and Primidone 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.
Donepezil belongs to Central Nervous System; Primidone belongs to Central Nervous System.
Why it happens
Enzyme induction (CYP3A4) by primidone and its phenobarbital metabolite increases donepezil clearance.
What to do
Monitor cognitive response and consider donepezil dose adjustment; reassess if primidone is discontinued.
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
Other interactions of Primidone
- Lorlatinib + Primidone Contraindicated
- Lurasidone + Primidone Contraindicated
- Primidone + Ranolazine Contraindicated
- Primidone + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
- Primidone + Voriconazole Contraindicated
- Abiraterone + Primidone Major
Frequently asked questions
Can I take Donepezil with Primidone?
MediHelp rates the interaction as moderate. Donepezil and Primidone 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. Primidone is metabolized to phenobarbital, an inducer of CYP3A4, and may reduce donepezil exposure over time. Loss of therapeutic effect is possible.
How serious is the interaction between Donepezil and Primidone?
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 cognitive response and consider donepezil dose adjustment; reassess if primidone is discontinued.
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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