Drug interactions
Marijuana + Memantine-donepezil
Severity: Minor
Marijuana and Memantine-donepezil: minor 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
Cannabis constituents can inhibit CYP enzymes in vitro, but there is no solid clinical evidence of a meaningful rise in donepezil levels. Cannabis may add to cognitive impairment and sedation in patients with dementia.
What this interaction means in plain words
Marijuana and Memantine-donepezil have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Possible weak CYP2D6 and CYP3A4 inhibition by cannabinoids; clinical relevance unproven.
What to do
Monitor for cognitive worsening, sedation and cholinergic effects such as bradycardia. Discourage cannabis use in patients with dementia.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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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 Marijuana with Memantine-donepezil?
MediHelp rates the interaction as minor. Marijuana and Memantine-donepezil have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Cannabis constituents can inhibit CYP enzymes in vitro, but there is no solid clinical evidence of a meaningful rise in donepezil levels. Cannabis may add to cognitive impairment and sedation in patients with dementia.
How serious is the interaction between Marijuana and Memantine-donepezil?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for cognitive worsening, sedation and cholinergic effects such as bradycardia. Discourage cannabis use in patients with dementia.
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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