Drug interactions
Donepezil + Orphenadrin
Severity: Moderate
Donepezil and Orphenadrin: 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 blocks muscarinic receptors and can oppose the cholinergic benefit of donepezil in dementia. The result may be reduced cognitive effect and worsened confusion, while orphenadrine can also impair cognition on its own.
What this interaction means in plain words
Donepezil and Orphenadrin 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; Orphenadrin belongs to Musculoskeletal.
Why it happens
Pharmacodynamic antagonism between a cholinesterase inhibitor and an antimuscarinic agent.
What to do
Avoid orphenadrine in patients taking donepezil when an alternative muscle relaxant or analgesic strategy is available. If continued, monitor cognition and function.
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 Orphenadrin
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 Orphenadrin?
MediHelp rates the interaction as moderate. Donepezil and Orphenadrin 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 blocks muscarinic receptors and can oppose the cholinergic benefit of donepezil in dementia. The result may be reduced cognitive effect and worsened confusion, while orphenadrine can also impair cognition on its own.
How serious is the interaction between Donepezil and Orphenadrin?
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 taking donepezil when an alternative muscle relaxant or analgesic strategy is available. If continued, monitor cognition and function.
What other medicines interact with Orphenadrin?
MediHelp also lists interactions of Orphenadrin with, for example, Alfentanil, Amobarbital, Benzhydrocodone / acetaminophen. The full list is on the Orphenadrin page.
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