Drug interactions
Oxybutynin transdermal + Trospium
Severity: Moderate
Oxybutynin transdermal and Trospium: 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
Both are bladder antimuscarinics, so combining them duplicates therapy and increases anticholinergic adverse effects. Dry mouth, constipation, urinary retention and cognitive effects are more likely.
What this interaction means in plain words
Oxybutynin transdermal and Trospium 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
Additive antimuscarinic pharmacodynamic effects.
What to do
Avoid using two antimuscarinics for overactive bladder; choose one agent and optimize its dose.
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 Trospium
- Clozapine + Trospium Major
- Pramlintide + Trospium Major
- Thioridazine + Trospium Major
- Trihexyphenidyl + Trospium Major
- Aclidinium + Trospium Moderate
- Amantadine + Trospium Moderate
Frequently asked questions
Can I take Oxybutynin transdermal with Trospium?
MediHelp rates the interaction as moderate. Oxybutynin transdermal and Trospium 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. Both are bladder antimuscarinics, so combining them duplicates therapy and increases anticholinergic adverse effects. Dry mouth, constipation, urinary retention and cognitive effects are more likely.
How serious is the interaction between Oxybutynin transdermal and Trospium?
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 using two antimuscarinics for overactive bladder; choose one agent and optimize its dose.
What other medicines interact with Trospium?
MediHelp also lists interactions of Trospium with, for example, Clozapine, Pramlintide, Thioridazine. The full list is on the Trospium page.
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