Drug interactions
Arsenic trioxide + Donepezil
Severity: Major
Arsenic trioxide and Donepezil: major interaction.
Last updated Sources: UK SmPC
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
Arsenic trioxide markedly prolongs the QT interval and can cause torsades de pointes. Donepezil has also been associated with QT prolongation and torsades, so combining them adds to arrhythmic risk, especially with electrolyte disturbances or bradycardia.
What this interaction means in plain words
Arsenic trioxide and 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.
Arsenic trioxide belongs to Oncology; Donepezil belongs to Central Nervous System.
Why it happens
Additive prolongation of cardiac repolarization through effects on cardiac potassium channels.
What to do
Avoid the combination where possible, or obtain a baseline ECG and correct potassium and magnesium before starting. Monitor QTc regularly during co-treatment.
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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References
- Apozyl 10 mg Orodispersible Tablets - SmPC sections 4.3/4.5 (class statement: other medicinal products known to prolong the QTc interval; "Caution is advised when donepezil is used in combination with other medicinal products known to prolong the QTc interval and clinical monitoring(ECG) may be req… — electronic medicines compendium (UK SmPC)
Other interactions of Donepezil
- Donepezil + Dronedarone Contraindicated
- Donepezil + Pimozide Contraindicated
- Donepezil + Thioridazine Contraindicated
- Donepezil + Vandetanib Contraindicated
- Amiodarone + Donepezil Major
- Amisulpride + Donepezil Major
Other interactions of Arsenic trioxide
- Amiodarone + Arsenic trioxide Contraindicated
- Amisulpride + Arsenic trioxide Contraindicated
- Arsenic trioxide + Clomipramine Contraindicated
- Arsenic trioxide + Dronedarone Contraindicated
- Arsenic trioxide + Fluphenazine Contraindicated
- Arsenic trioxide + Gemifloxacin Contraindicated
Frequently asked questions
Can I take Arsenic trioxide with Donepezil?
MediHelp rates the interaction as major. Arsenic trioxide and 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. Arsenic trioxide markedly prolongs the QT interval and can cause torsades de pointes. Donepezil has also been associated with QT prolongation and torsades, so combining them adds to arrhythmic risk, especially with electrolyte disturbances or bradycardia.
How serious is the interaction between Arsenic trioxide and 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: Avoid the combination where possible, or obtain a baseline ECG and correct potassium and magnesium before starting. Monitor QTc regularly during co-treatment.
What other medicines interact with Donepezil?
MediHelp also lists interactions of Donepezil with, for example, Dronedarone, Pimozide, Thioridazine. The full list is on the Donepezil page.
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