Drug interactions
Memantine-donepezil + Orphenadrine
Severity: Moderate
Memantine-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 substantial anticholinergic activity that opposes donepezil and can worsen memory and confusion in dementia. It may also contribute to tachycardia and delirium in older patients.
What this interaction means in plain words
Memantine-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
Muscarinic antagonism counteracts cholinesterase inhibition.
What to do
Avoid in patients with dementia and choose a non-anticholinergic muscle relaxant. If unavoidable, use the lowest dose briefly and monitor cognition.
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 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
Frequently asked questions
Can I take Memantine-donepezil with Orphenadrine?
MediHelp rates the interaction as moderate. Memantine-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 substantial anticholinergic activity that opposes donepezil and can worsen memory and confusion in dementia. It may also contribute to tachycardia and delirium in older patients.
How serious is the interaction between Memantine-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 in patients with dementia and choose a non-anticholinergic muscle relaxant. If unavoidable, use the lowest dose briefly and monitor cognition.
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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