Drug interactions
Memantine-donepezil + Primidone
Severity: Minor
Memantine-donepezil and Primidone: minor 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 partly converted to phenobarbital, an enzyme inducer, so it may reduce donepezil exposure and weaken its effect over time. The clinical significance is usually small. Additive sedation from primidone may also occur in older patients with dementia.
What this interaction means in plain words
Memantine-donepezil and Primidone have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Memantine-donepezil belongs to Central Nervous System; Primidone belongs to Central Nervous System.
Why it happens
Primidone and its metabolite phenobarbital induce CYP3A4, increasing donepezil metabolism.
What to do
Monitor cognitive and functional response when primidone is started, changed or stopped, and adjust the donepezil dose if benefit declines. Monitor for excess sedation and falls.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Memantine-donepezil
- Dronedarone + Memantine-donepezil Contraindicated
- Memantine-donepezil + Thioridazine Contraindicated
- Amantadine + Memantine-donepezil Major
- Amiodarone + Memantine-donepezil Major
- Amisulpride + Memantine-donepezil Major
- Amitriptyline + Memantine-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 Memantine-donepezil with Primidone?
MediHelp rates the interaction as minor. Memantine-donepezil and Primidone have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Primidone is partly converted to phenobarbital, an enzyme inducer, so it may reduce donepezil exposure and weaken its effect over time. The clinical significance is usually small. Additive sedation from primidone may also occur in older patients with dementia.
How serious is the interaction between Memantine-donepezil and Primidone?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor cognitive and functional response when primidone is started, changed or stopped, and adjust the donepezil dose if benefit declines. Monitor for excess sedation and falls.
What other medicines interact with Memantine-donepezil?
MediHelp also lists interactions of Memantine-donepezil with, for example, Dronedarone, Thioridazine, Amantadine. The full list is on the Memantine-donepezil page.
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