Drug interactions
Physostigmine + Pyridostigmine
Severity: Major
Physostigmine and Pyridostigmine: 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 are cholinesterase inhibitors, so combining them produces additive cholinergic effects including bradycardia, bronchospasm, secretions, seizures and cholinergic crisis with worsened weakness.
What this interaction means in plain words
Physostigmine and Pyridostigmine 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 needed; if used, monitor heart rate, respiratory function and muscle strength closely 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 Pyridostigmine
Frequently asked questions
Can I take Physostigmine with Pyridostigmine?
MediHelp rates the interaction as major. Physostigmine and Pyridostigmine 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 combining them produces additive cholinergic effects including bradycardia, bronchospasm, secretions, seizures and cholinergic crisis with worsened weakness.
How serious is the interaction between Physostigmine and Pyridostigmine?
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 needed; if used, monitor heart rate, respiratory function and muscle strength closely with atropine available.
What other medicines interact with Pyridostigmine?
MediHelp also lists interactions of Pyridostigmine with, for example, Echothiophate iodide, Huperzine a, Neostigmine. The full list is on the Pyridostigmine page.
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