Drug interactions
Belladonna alkaloids + Tolterodine
Severity: Moderate
Belladonna alkaloids and Tolterodine: 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
Belladonna alkaloids such as hyoscyamine and scopolamine are antimuscarinic and may add to the effects of tolterodine. This may cause dry mouth, constipation, urinary retention, blurred vision, tachycardia and confusion.
What this interaction means in plain words
Belladonna alkaloids and Tolterodine 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 muscarinic receptor blockade.
What to do
Avoid duplicate antimuscarinic therapy when possible. If used together, monitor for urinary retention, constipation, and cognitive or visual changes.
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 Belladonna alkaloids and Tolterodine, 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 14 days on the web. No card needed.
Other interactions of Tolterodine
Frequently asked questions
Can I take Belladonna alkaloids with Tolterodine?
MediHelp rates the interaction as moderate. Belladonna alkaloids and Tolterodine 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. Belladonna alkaloids such as hyoscyamine and scopolamine are antimuscarinic and may add to the effects of tolterodine. This may cause dry mouth, constipation, urinary retention, blurred vision, tachycardia and confusion.
How serious is the interaction between Belladonna alkaloids and Tolterodine?
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 duplicate antimuscarinic therapy when possible. If used together, monitor for urinary retention, constipation, and cognitive or visual changes.
What other medicines interact with Tolterodine?
MediHelp also lists interactions of Tolterodine with, for example, Clarithromycin, Clozapine, Cobicistat. The full list is on the Tolterodine 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.
