Drug interactions
Neostigmine + Oxybutynin
Severity: Moderate
Neostigmine and Oxybutynin: 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
Neostigmine increases acetylcholine at receptors while oxybutynin blocks muscarinic receptors, so the two drugs oppose each other. Oxybutynin may reduce the effect of neostigmine on gut or bladder motility and muscarinic effects.
What this interaction means in plain words
Neostigmine and Oxybutynin 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.
Neostigmine belongs to Central Nervous System; Oxybutynin belongs to Genitourinary.
Why it happens
Pharmacodynamic antagonism between a cholinesterase inhibitor and a muscarinic antagonist.
What to do
Monitor response to neostigmine, including bladder or bowel function, and avoid oxybutynin when neostigmine is used to treat retention or ileus. In myasthenia gravis, watch for changes in symptom control.
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 Oxybutynin
Other interactions of Neostigmine
Frequently asked questions
Can I take Neostigmine with Oxybutynin?
MediHelp rates the interaction as moderate. Neostigmine and Oxybutynin 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. Neostigmine increases acetylcholine at receptors while oxybutynin blocks muscarinic receptors, so the two drugs oppose each other. Oxybutynin may reduce the effect of neostigmine on gut or bladder motility and muscarinic effects.
How serious is the interaction between Neostigmine and Oxybutynin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor response to neostigmine, including bladder or bowel function, and avoid oxybutynin when neostigmine is used to treat retention or ileus. In myasthenia gravis, watch for changes in symptom control.
What other medicines interact with Oxybutynin?
MediHelp also lists interactions of Oxybutynin with, for example, Bethanechol, Clozapine, Potassium chloride. The full list is on the Oxybutynin page.
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