Drug interactions
Memantine-donepezil + Tetrabenazine
Severity: Major
Memantine-donepezil and Tetrabenazine: major 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
Tetrabenazine causes dose-related QT prolongation and donepezil can also prolong QT. The combination raises the risk of ventricular arrhythmia.
What this interaction means in plain words
Memantine-donepezil and Tetrabenazine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Memantine-donepezil belongs to Central Nervous System; Tetrabenazine belongs to Central Nervous System.
Why it happens
Additive QT interval prolongation.
What to do
Avoid combining if possible, and keep the tetrabenazine dose as low as effective. If both are needed, monitor ECG and correct electrolytes.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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 Tetrabenazine
- Dronedarone + Tetrabenazine Contraindicated
- Isocarboxazid + Tetrabenazine Contraindicated
- Linezolid + Tetrabenazine Contraindicated
- Phenelzine + Tetrabenazine Contraindicated
- Pimozide + Tetrabenazine Contraindicated
- Procarbazine + Tetrabenazine Contraindicated
Frequently asked questions
Can I take Memantine-donepezil with Tetrabenazine?
MediHelp rates the interaction as major. Memantine-donepezil and Tetrabenazine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Tetrabenazine causes dose-related QT prolongation and donepezil can also prolong QT. The combination raises the risk of ventricular arrhythmia.
How serious is the interaction between Memantine-donepezil and Tetrabenazine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid combining if possible, and keep the tetrabenazine dose as low as effective. If both are needed, monitor ECG and correct electrolytes.
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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