Drug interactions
Donepezil + Erythromycin
Severity: Major
Donepezil and Erythromycin: major interaction.
Last updated Sources: US FDA label
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
Both drugs can prolong the QT interval, and erythromycin may raise donepezil levels. This increases the risk of torsades de pointes and cholinergic effects such as bradycardia.
What this interaction means in plain words
Donepezil and Erythromycin 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.
Donepezil belongs to Central Nervous System; Erythromycin belongs to Anti Bacterial.
Why it happens
Additive QT prolongation with CYP3A4 inhibition raising donepezil exposure.
What to do
Use a non-QT-prolonging antibiotic when possible. If combined, check ECG and electrolytes and monitor for bradycardia and syncope.
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
Other interactions of Erythromycin
- Conivaptan + Erythromycin Contraindicated
- Dihydroergotamine intranasal + Erythromycin Contraindicated
- Dihydroergotamine + Erythromycin Contraindicated
- Domperidone + Erythromycin Contraindicated
- Dronedarone + Erythromycin Contraindicated
- Droperidol + Erythromycin Contraindicated
Other interactions of Donepezil
- Donepezil + Dronedarone Contraindicated
- Donepezil + Pimozide Contraindicated
- Donepezil + Thioridazine Contraindicated
- Donepezil + Vandetanib Contraindicated
- Amiodarone + Donepezil Major
- Amisulpride + Donepezil Major
Frequently asked questions
Can I take Donepezil with Erythromycin?
MediHelp rates the interaction as major. Donepezil and Erythromycin 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. Both drugs can prolong the QT interval, and erythromycin may raise donepezil levels. This increases the risk of torsades de pointes and cholinergic effects such as bradycardia.
How serious is the interaction between Donepezil and Erythromycin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use a non-QT-prolonging antibiotic when possible. If combined, check ECG and electrolytes and monitor for bradycardia and syncope.
What other medicines interact with Erythromycin?
MediHelp also lists interactions of Erythromycin with, for example, Conivaptan, Dihydroergotamine intranasal, Dihydroergotamine. The full list is on the Erythromycin page.
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