Drug interactions
Memantine-donepezil + Ondansetron
Severity: Moderate
Memantine-donepezil and Ondansetron: 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
Ondansetron prolongs the QT interval in a dose-dependent manner, particularly with intravenous dosing. Donepezil may add to QT prolongation and bradycardia, which can increase the risk of torsades de pointes.
What this interaction means in plain words
Memantine-donepezil and Ondansetron 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.
Memantine-donepezil belongs to Central Nervous System; Ondansetron belongs to Gastrointestinal Tract.
Why it happens
Additive pharmacodynamic QT prolongation.
What to do
Use the lowest effective ondansetron dose, avoid large single intravenous doses, and check the ECG in patients with other risk factors. Correct hypokalemia and hypomagnesemia first.
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 Ondansetron
- Apomorphine + Ondansetron Contraindicated
- Ondansetron + Thioridazine Contraindicated
- Ondansetron + Vandetanib Contraindicated
- Adagrasib + Ondansetron Major
- Amiodarone + Ondansetron Major
- Amisulpride + Ondansetron Major
Frequently asked questions
Can I take Memantine-donepezil with Ondansetron?
MediHelp rates the interaction as moderate. Memantine-donepezil and Ondansetron 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. Ondansetron prolongs the QT interval in a dose-dependent manner, particularly with intravenous dosing. Donepezil may add to QT prolongation and bradycardia, which can increase the risk of torsades de pointes.
How serious is the interaction between Memantine-donepezil and Ondansetron?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use the lowest effective ondansetron dose, avoid large single intravenous doses, and check the ECG in patients with other risk factors. Correct hypokalemia and hypomagnesemia first.
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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