Drug interactions
Memantine-donepezil + Protriptyline
Severity: Moderate
Memantine-donepezil and Protriptyline: 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
Protriptyline is a strongly anticholinergic tricyclic antidepressant that can counteract donepezil and worsen cognition in dementia. Both drugs can also prolong the QT interval, and donepezil may cause bradycardia, which raises arrhythmia risk.
What this interaction means in plain words
Memantine-donepezil and Protriptyline 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
Anticholinergic antagonism of cholinesterase inhibition plus additive QT prolongation and bradycardic effects.
What to do
Prefer an antidepressant with low anticholinergic activity; if the combination is needed, obtain a baseline ECG and monitor QTc, heart rate and 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 Protriptyline?
MediHelp rates the interaction as moderate. Memantine-donepezil and Protriptyline 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. Protriptyline is a strongly anticholinergic tricyclic antidepressant that can counteract donepezil and worsen cognition in dementia. Both drugs can also prolong the QT interval, and donepezil may cause bradycardia, which raises arrhythmia risk.
How serious is the interaction between Memantine-donepezil and Protriptyline?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer an antidepressant with low anticholinergic activity; if the combination is needed, obtain a baseline ECG and monitor QTc, heart rate and 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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