Drug interactions
Ketoconazole + Memantine-donepezil
Severity: Moderate
Ketoconazole 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
Ketoconazole inhibits CYP3A4 and increases donepezil concentrations, which may increase cholinergic adverse effects such as bradycardia, nausea and vomiting. Ketoconazole itself also prolongs the QT interval.
What this interaction means in plain words
Ketoconazole 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.
Ketoconazole belongs to Anti Fungals; Memantine-donepezil belongs to Central Nervous System.
Why it happens
Inhibition of CYP3A4-mediated donepezil metabolism, with additive QT prolongation.
What to do
Monitor heart rate, QTc and cholinergic effects, and reduce the donepezil dose if these occur. Consider an alternative antifungal where possible.
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
Other interactions of Ketoconazole
- Alfuzosin + Ketoconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Avanafil + Ketoconazole Contraindicated
- Conivaptan + Ketoconazole Contraindicated
- Dihydroergotamine intranasal + Ketoconazole Contraindicated
- Dihydroergotamine + Ketoconazole Contraindicated
Frequently asked questions
Can I take Ketoconazole with Memantine-donepezil?
MediHelp rates the interaction as moderate. Ketoconazole 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. Ketoconazole inhibits CYP3A4 and increases donepezil concentrations, which may increase cholinergic adverse effects such as bradycardia, nausea and vomiting. Ketoconazole itself also prolongs the QT interval.
How serious is the interaction between Ketoconazole 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, QTc and cholinergic effects, and reduce the donepezil dose if these occur. Consider an alternative antifungal where possible.
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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