Drug interactions
Donepezil + Physostigmine
Severity: Major
Donepezil and Physostigmine: 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 are cholinesterase inhibitors, so combined use can cause additive cholinergic toxicity. This may present as bradycardia, bronchospasm, excess secretions, vomiting and seizures.
What this interaction means in plain words
Donepezil and Physostigmine 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.
Why it happens
Additive acetylcholinesterase inhibition.
What to do
Avoid using the two together unless physostigmine is needed for a specific indication. Monitor heart rate, respiration and cholinergic signs, and have atropine available.
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 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 Physostigmine?
MediHelp rates the interaction as major. Donepezil and Physostigmine 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 are cholinesterase inhibitors, so combined use can cause additive cholinergic toxicity. This may present as bradycardia, bronchospasm, excess secretions, vomiting and seizures.
How serious is the interaction between Donepezil and Physostigmine?
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 using the two together unless physostigmine is needed for a specific indication. Monitor heart rate, respiration and cholinergic signs, and have atropine available.
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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