Drug interactions
Physostigmine + Scopolamine
Severity: Moderate
Physostigmine and Scopolamine: 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 raises acetylcholine, whereas scopolamine blocks muscarinic receptors, so each opposes the other's effect. Physostigmine is used deliberately to reverse anticholinergic toxicity from scopolamine, which can reduce or abolish scopolamine's intended effects.
What this interaction means in plain words
Physostigmine and Scopolamine 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 a cholinesterase inhibitor and a muscarinic antagonist.
What to do
Avoid giving them together unless reversing scopolamine toxicity; in that case titrate physostigmine slowly with cardiac monitoring because of bradycardia and seizure risk.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Physostigmine and Scopolamine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Scopolamine
Frequently asked questions
Can I take Physostigmine with Scopolamine?
MediHelp rates the interaction as moderate. Physostigmine and Scopolamine 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 raises acetylcholine, whereas scopolamine blocks muscarinic receptors, so each opposes the other's effect. Physostigmine is used deliberately to reverse anticholinergic toxicity from scopolamine, which can reduce or abolish scopolamine's intended effects.
How serious is the interaction between Physostigmine and Scopolamine?
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 giving them together unless reversing scopolamine toxicity; in that case titrate physostigmine slowly with cardiac monitoring because of bradycardia and seizure risk.
What other medicines interact with Scopolamine?
MediHelp also lists interactions of Scopolamine with, for example, Benzhydrocodone / acetaminophen, Buprenorphine long-acting, Buprenorphine subdermal implant. The full list is on the Scopolamine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
