Drug interactions
Oxybutynin + Trospium
Severity: Moderate
Oxybutynin 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 antimuscarinic agents for overactive bladder, and combining them adds to the antimuscarinic burden. This raises the risk of dry mouth, constipation, blurred vision, urinary retention and, with oxybutynin, cognitive effects.
What this interaction means in plain words
Oxybutynin 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.
Oxybutynin belongs to Genitourinary; Trospium belongs to Genitourinary.
Why it happens
Additive muscarinic receptor antagonism.
What to do
Avoid routine duplication of bladder antimuscarinics and use a single agent at an optimized dose. If both are used, monitor for anticholinergic toxicity and post-void residual volume.
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
Other interactions of Oxybutynin
Frequently asked questions
Can I take Oxybutynin with Trospium?
MediHelp rates the interaction as moderate. Oxybutynin 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 antimuscarinic agents for overactive bladder, and combining them adds to the antimuscarinic burden. This raises the risk of dry mouth, constipation, blurred vision, urinary retention and, with oxybutynin, cognitive effects.
How serious is the interaction between Oxybutynin 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 routine duplication of bladder antimuscarinics and use a single agent at an optimized dose. If both are used, monitor for anticholinergic toxicity and post-void residual volume.
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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