Drug interactions
Darifenacin + Ritonavir
Severity: Major
Darifenacin and Ritonavir: major 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
Ritonavir is a strong CYP3A4 inhibitor and can markedly increase darifenacin exposure, raising the risk of anticholinergic adverse effects. Darifenacin has little effect on ritonavir.
What this interaction means in plain words
Darifenacin and Ritonavir can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Darifenacin belongs to Genitourinary; Ritonavir belongs to Anti Virals.
Why it happens
Ritonavir inhibits CYP3A4-mediated darifenacin metabolism.
What to do
Limit darifenacin to 7.5 mg daily with potent CYP3A4 inhibitors, as labeled, and monitor for dry mouth, constipation, and urinary retention.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Darifenacin and Ritonavir, 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
Other interactions of Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Frequently asked questions
Can I take Darifenacin with Ritonavir?
MediHelp rates the interaction as major. Darifenacin and Ritonavir can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Ritonavir is a strong CYP3A4 inhibitor and can markedly increase darifenacin exposure, raising the risk of anticholinergic adverse effects. Darifenacin has little effect on ritonavir.
How serious is the interaction between Darifenacin and Ritonavir?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Limit darifenacin to 7.5 mg daily with potent CYP3A4 inhibitors, as labeled, and monitor for dry mouth, constipation, and urinary retention.
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.
