Drug interactions
Tolterodine + Verapamil
Severity: Moderate
Tolterodine and Verapamil: 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
Verapamil inhibits CYP3A4 and P-glycoprotein and may raise tolterodine exposure. Tolterodine is mainly cleared by CYP2D6, so the effect is usually modest. Higher concentrations may increase anticholinergic effects and QT risk.
What this interaction means in plain words
Tolterodine and Verapamil 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.
Tolterodine belongs to Genitourinary; Verapamil belongs to Cardiovascular.
Why it happens
Inhibition of CYP3A4 metabolism of tolterodine by verapamil.
What to do
Monitor for anticholinergic adverse effects. Reduce the tolterodine dose if they develop, particularly in CYP2D6 poor metabolizers.
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 Tolterodine and Verapamil, 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
Other interactions of Verapamil
- Dofetilide + Verapamil Contraindicated
- Flibanserin + Verapamil Contraindicated
- Lomitapide + Verapamil Contraindicated
- Lonafarnib + Verapamil Contraindicated
- Pimozide + Verapamil Contraindicated
- Acebutolol + Verapamil Major
Frequently asked questions
Can I take Tolterodine with Verapamil?
MediHelp rates the interaction as moderate. Tolterodine and Verapamil 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. Verapamil inhibits CYP3A4 and P-glycoprotein and may raise tolterodine exposure. Tolterodine is mainly cleared by CYP2D6, so the effect is usually modest. Higher concentrations may increase anticholinergic effects and QT risk.
How serious is the interaction between Tolterodine and Verapamil?
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 for anticholinergic adverse effects. Reduce the tolterodine dose if they develop, particularly in CYP2D6 poor metabolizers.
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.
