Drug interactions
Fosamprenavir + Memantine-donepezil
Severity: Moderate
Fosamprenavir and Memantine-donepezil: 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
Fosamprenavir is converted to amprenavir, a CYP3A4 inhibitor, especially when boosted with ritonavir. Donepezil exposure may rise, increasing cholinergic effects such as bradycardia and gastrointestinal upset.
What this interaction means in plain words
Fosamprenavir and Memantine-donepezil 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
Amprenavir, with or without ritonavir, inhibits CYP3A4-mediated donepezil metabolism.
What to do
Monitor heart rate and cholinergic adverse effects. Reduce the donepezil dose if they occur.
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 Fosamprenavir with Memantine-donepezil?
MediHelp rates the interaction as moderate. Fosamprenavir and Memantine-donepezil 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. Fosamprenavir is converted to amprenavir, a CYP3A4 inhibitor, especially when boosted with ritonavir. Donepezil exposure may rise, increasing cholinergic effects such as bradycardia and gastrointestinal upset.
How serious is the interaction between Fosamprenavir and Memantine-donepezil?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor heart rate and cholinergic adverse effects. Reduce the donepezil dose if they occur.
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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