Drug interactions
Atropine + Physostigmine
Severity: Moderate
Atropine and Physostigmine: moderate 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 acetylcholinesterase and atropine blocks muscarinic receptors, so each opposes the other. This opposition is used therapeutically to reverse anticholinergic toxicity but means that combined use reduces the effect of both.
What this interaction means in plain words
Atropine and Physostigmine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Pharmacodynamic antagonism between cholinesterase inhibition and muscarinic receptor blockade.
What to do
Avoid combining unless intended, such as using atropine to treat physostigmine-induced cholinergic excess. Have atropine available when giving physostigmine and monitor heart rate and secretions.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Atropine
- Atropine + Eluxadoline Major
- Atropine + Henbane Major
- Atropine + Pramlintide Major
- Abobotulinumtoxina + Atropine Moderate
- Aclidinium + Atropine Moderate
- Amantadine + Atropine Moderate
Frequently asked questions
Can I take Atropine with Physostigmine?
MediHelp rates the interaction as moderate. Atropine and Physostigmine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Physostigmine inhibits acetylcholinesterase and atropine blocks muscarinic receptors, so each opposes the other. This opposition is used therapeutically to reverse anticholinergic toxicity but means that combined use reduces the effect of both.
How serious is the interaction between Atropine and Physostigmine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid combining unless intended, such as using atropine to treat physostigmine-induced cholinergic excess. Have atropine available when giving physostigmine and monitor heart rate and secretions.
What other medicines interact with Atropine?
MediHelp also lists interactions of Atropine with, for example, Eluxadoline, Henbane, Pramlintide. The full list is on the Atropine page.
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