Drug interactions
Donepezil + Orphenadrine
Severity: Moderate
Donepezil and Orphenadrine: 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
Orphenadrine has strong anticholinergic properties that oppose donepezil's pharmacologic action. This can reduce cognitive benefit and worsen confusion in older patients.
What this interaction means in plain words
Donepezil and Orphenadrine 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
Pharmacodynamic antagonism between antimuscarinic activity and cholinesterase inhibition.
What to do
Avoid orphenadrine in patients with dementia and use a non-anticholinergic muscle relaxant or analgesic. Monitor cognition if it cannot be avoided.
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 Orphenadrine?
MediHelp rates the interaction as moderate. Donepezil and Orphenadrine 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. Orphenadrine has strong anticholinergic properties that oppose donepezil's pharmacologic action. This can reduce cognitive benefit and worsen confusion in older patients.
How serious is the interaction between Donepezil and Orphenadrine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid orphenadrine in patients with dementia and use a non-anticholinergic muscle relaxant or analgesic. Monitor cognition if it cannot be avoided.
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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