Drug interactions
Fluoxetine + Memantine-donepezil
Severity: Moderate
Fluoxetine 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
Fluoxetine is a strong CYP2D6 inhibitor and can increase donepezil concentrations, increasing cholinergic adverse effects. Both drugs can also prolong the QT interval, and combined use adds to the arrhythmia risk.
What this interaction means in plain words
Fluoxetine 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.
Fluoxetine belongs to Central Nervous System; Memantine-donepezil belongs to Central Nervous System.
Why it happens
CYP2D6 inhibition by fluoxetine reduces donepezil clearance, combined with additive QT prolongation.
What to do
Monitor heart rate, QTc and cholinergic effects such as nausea, bradycardia and syncope. Reduce the donepezil dose if adverse effects appear.
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 Fluoxetine
- Fluoxetine + Isocarboxazid Contraindicated
- Fluoxetine + Mavacamten Contraindicated
- Fluoxetine + Methylene blue Contraindicated
- Fluoxetine + Phenelzine Contraindicated
- Fluoxetine + Pimozide Contraindicated
- Fluoxetine + Rasagiline Contraindicated
Frequently asked questions
Can I take Fluoxetine with Memantine-donepezil?
MediHelp rates the interaction as moderate. Fluoxetine 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. Fluoxetine is a strong CYP2D6 inhibitor and can increase donepezil concentrations, increasing cholinergic adverse effects. Both drugs can also prolong the QT interval, and combined use adds to the arrhythmia risk.
How serious is the interaction between Fluoxetine 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 such as nausea, bradycardia and syncope. Reduce the donepezil dose if adverse effects appear.
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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