Drug interactions
Darifenacin + Protriptyline
Severity: Moderate
Darifenacin and Protriptyline: 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
Protriptyline is a strongly anticholinergic tricyclic antidepressant, which adds to the antimuscarinic effects of darifenacin. Darifenacin's CYP2D6 inhibition may also raise protriptyline levels, increasing the risk of cardiac and anticholinergic effects.
What this interaction means in plain words
Darifenacin and Protriptyline 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 antagonism plus possible CYP2D6 inhibition by darifenacin.
What to do
Monitor for anticholinergic toxicity, tachycardia, and urinary retention, and consider an ECG or lower protriptyline dose in older or cardiac patients.
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 Protriptyline, 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 Darifenacin
Frequently asked questions
Can I take Darifenacin with Protriptyline?
MediHelp rates the interaction as moderate. Darifenacin and Protriptyline 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. Protriptyline is a strongly anticholinergic tricyclic antidepressant, which adds to the antimuscarinic effects of darifenacin. Darifenacin's CYP2D6 inhibition may also raise protriptyline levels, increasing the risk of cardiac and anticholinergic effects.
How serious is the interaction between Darifenacin and Protriptyline?
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 toxicity, tachycardia, and urinary retention, and consider an ECG or lower protriptyline dose in older or cardiac patients.
What other medicines interact with Darifenacin?
MediHelp also lists interactions of Darifenacin with, for example, Atazanavir, Bethanechol, Clarithromycin. The full list is on the Darifenacin 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.
