Drug interactions
Amitriptyline + Memantine-donepezil
Severity: Major
Amitriptyline and Memantine-donepezil: major 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
Amitriptyline has strong anticholinergic activity that directly opposes the cholinergic effect of donepezil, potentially reducing dementia benefit and worsening cognition. Both drugs can also prolong the QT interval.
What this interaction means in plain words
Amitriptyline and Memantine-donepezil can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Amitriptyline belongs to Central Nervous System; Memantine-donepezil belongs to Central Nervous System.
Why it happens
Anticholinergic antagonism of cholinesterase inhibition, plus additive QT prolongation.
What to do
Avoid amitriptyline in dementia patients if possible and choose a less anticholinergic alternative. If used, monitor cognition and ECG.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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
- Anagrelide + Memantine-donepezil Major
Other interactions of Amitriptyline
- Amitriptyline + Isocarboxazid Contraindicated
- Amitriptyline + Methylene blue Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amitriptyline + Procarbazine Contraindicated
- Amitriptyline + Safinamide Contraindicated
Frequently asked questions
Can I take Amitriptyline with Memantine-donepezil?
MediHelp rates the interaction as major. Amitriptyline and Memantine-donepezil can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Amitriptyline has strong anticholinergic activity that directly opposes the cholinergic effect of donepezil, potentially reducing dementia benefit and worsening cognition. Both drugs can also prolong the QT interval.
How serious is the interaction between Amitriptyline and Memantine-donepezil?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid amitriptyline in dementia patients if possible and choose a less anticholinergic alternative. If used, monitor cognition and ECG.
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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