Drug interactions
Neostigmine + Physostigmine
Severity: Major
Neostigmine 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
Both drugs inhibit cholinesterase, so combined use gives additive cholinergic effects. Bradycardia, bronchospasm, excessive secretions, vomiting, seizures and cholinergic crisis are possible.
What this interaction means in plain words
Neostigmine 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 combining unless specifically intended; if used, monitor heart rate, respiration and secretions, with 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 Neostigmine
Frequently asked questions
Can I take Neostigmine with Physostigmine?
MediHelp rates the interaction as major. Neostigmine 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 drugs inhibit cholinesterase, so combined use gives additive cholinergic effects. Bradycardia, bronchospasm, excessive secretions, vomiting, seizures and cholinergic crisis are possible.
How serious is the interaction between Neostigmine 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 combining unless specifically intended; if used, monitor heart rate, respiration and secretions, with atropine available.
What other medicines interact with Neostigmine?
MediHelp also lists interactions of Neostigmine with, for example, Huperzine a, Pyridostigmine, Succinylcholine. The full list is on the Neostigmine page.
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