Drug interactions
Bethanechol + Physostigmine
Severity: Major
Bethanechol and Physostigmine: 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
Physostigmine inhibits cholinesterase and increases acetylcholine, adding to the direct muscarinic stimulation of bethanechol. This can cause marked cholinergic toxicity including bradycardia, bronchospasm, salivation, vomiting and cramping.
What this interaction means in plain words
Bethanechol 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 cholinergic effect from direct muscarinic agonism plus inhibition of acetylcholine breakdown.
What to do
Avoid the combination where possible. If used, monitor heart rate, respiratory status and gastrointestinal symptoms, 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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Other interactions of Bethanechol
- Bethanechol + Darifenacin Major
- Bethanechol + Fesoterodine Major
- Bethanechol + Oxybutynin Major
- Amifampridine + Bethanechol Moderate
- Amitriptyline + Bethanechol Moderate
- Amoxapine + Bethanechol Moderate
Frequently asked questions
Can I take Bethanechol with Physostigmine?
MediHelp rates the interaction as major. Bethanechol 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. Physostigmine inhibits cholinesterase and increases acetylcholine, adding to the direct muscarinic stimulation of bethanechol. This can cause marked cholinergic toxicity including bradycardia, bronchospasm, salivation, vomiting and cramping.
How serious is the interaction between Bethanechol 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 the combination where possible. If used, monitor heart rate, respiratory status and gastrointestinal symptoms, and have atropine available.
What other medicines interact with Bethanechol?
MediHelp also lists interactions of Bethanechol with, for example, Darifenacin, Fesoterodine, Oxybutynin. The full list is on the Bethanechol page.
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