Drug interactions
Haloperidol + Memantine-donepezil
Severity: Major
Haloperidol and Memantine-donepezil: 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
Haloperidol and donepezil can each prolong the QT interval, and the combination raises the risk of torsades de pointes, particularly with intravenous haloperidol or electrolyte disturbances. Antipsychotic use in dementia also carries other safety risks.
What this interaction means in plain words
Haloperidol and Memantine-donepezil 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.
Haloperidol belongs to Central Nervous System; Memantine-donepezil belongs to Central Nervous System.
Why it happens
Additive QT prolongation; haloperidol antagonism of dopamine and cholinergic effects may also reduce donepezil benefit.
What to do
Obtain a baseline ECG, correct electrolytes and monitor the QTc during treatment. Use the lowest effective haloperidol dose for the shortest time and consider a safer alternative.
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 Haloperidol
- Dofetilide + Haloperidol Contraindicated
- Dronedarone + Haloperidol Contraindicated
- Haloperidol + Ibutilide Contraindicated
- Haloperidol + Levoketoconazole Contraindicated
- Haloperidol + Panobinostat Contraindicated
- Haloperidol + Pimozide Contraindicated
Frequently asked questions
Can I take Haloperidol with Memantine-donepezil?
MediHelp rates the interaction as major. Haloperidol and Memantine-donepezil 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. Haloperidol and donepezil can each prolong the QT interval, and the combination raises the risk of torsades de pointes, particularly with intravenous haloperidol or electrolyte disturbances. Antipsychotic use in dementia also carries other safety risks.
How serious is the interaction between Haloperidol and Memantine-donepezil?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG, correct electrolytes and monitor the QTc during treatment. Use the lowest effective haloperidol dose for the shortest time and consider a safer alternative.
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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