Drug interactions
Atazanavir + Darifenacin
Severity: Major
Atazanavir and Darifenacin: 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
Atazanavir is a strong CYP3A4 inhibitor and can substantially raise darifenacin exposure. This increases the risk of anticholinergic effects such as dry mouth, constipation, urinary retention and QT-related concerns at high concentrations.
What this interaction means in plain words
Atazanavir and Darifenacin 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.
Atazanavir belongs to Anti Virals; Darifenacin belongs to Genitourinary.
Why it happens
Inhibition of CYP3A4-mediated metabolism of darifenacin.
What to do
Limit darifenacin to 7.5 mg daily with strong CYP3A4 inhibitors and monitor for anticholinergic adverse effects, or choose an alternative.
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 Atazanavir and Darifenacin, 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 Darifenacin
Other interactions of Atazanavir
- Alfuzosin + Atazanavir Contraindicated
- Atazanavir + Avanafil Contraindicated
- Atazanavir + Dronedarone Contraindicated
- Atazanavir + Eletriptan Contraindicated
- Atazanavir + Eplerenone Contraindicated
- Atazanavir + Ergotamine Contraindicated
Frequently asked questions
Can I take Atazanavir with Darifenacin?
MediHelp rates the interaction as major. Atazanavir and Darifenacin 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. Atazanavir is a strong CYP3A4 inhibitor and can substantially raise darifenacin exposure. This increases the risk of anticholinergic effects such as dry mouth, constipation, urinary retention and QT-related concerns at high concentrations.
How serious is the interaction between Atazanavir and Darifenacin?
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 strong CYP3A4 inhibitors and monitor for anticholinergic adverse effects, or choose an alternative.
What other medicines interact with Darifenacin?
MediHelp also lists interactions of Darifenacin with, for example, Bethanechol, Clarithromycin, Clozapine. 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.
