Drug interactions
Darifenacin + Tolterodine
Severity: Moderate
Darifenacin 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
Both are antimuscarinic bladder agents, so combining them provides no therapeutic advantage and increases anticholinergic adverse effects such as dry mouth, constipation and urinary retention. Darifenacin is a CYP2D6 inhibitor and may also modestly raise tolterodine exposure.
What this interaction means in plain words
Darifenacin 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.
Darifenacin belongs to Genitourinary; Tolterodine belongs to Genitourinary.
Why it happens
Duplicate antimuscarinic activity, plus modest CYP2D6 inhibition by darifenacin.
What to do
Avoid using two antimuscarinic bladder agents together; use one at an optimized dose or switch to a beta-3 agonist.
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 Darifenacin 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 7 days on the web. No card needed.
Other interactions of Tolterodine
Other interactions of Darifenacin
Frequently asked questions
Can I take Darifenacin with Tolterodine?
MediHelp rates the interaction as moderate. Darifenacin 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. Both are antimuscarinic bladder agents, so combining them provides no therapeutic advantage and increases anticholinergic adverse effects such as dry mouth, constipation and urinary retention. Darifenacin is a CYP2D6 inhibitor and may also modestly raise tolterodine exposure.
How serious is the interaction between Darifenacin 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 using two antimuscarinic bladder agents together; use one at an optimized dose or switch to a beta-3 agonist.
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.
