Drug interactions
Darifenacin + Darunavir
Severity: Major
Darifenacin and Darunavir: 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
Darunavir, usually given with a booster such as ritonavir or cobicistat, strongly inhibits CYP3A4 and can substantially raise darifenacin levels. This increases the risk of anticholinergic toxicity.
What this interaction means in plain words
Darifenacin and Darunavir 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; Darunavir belongs to Anti Virals.
Why it happens
Inhibition of CYP3A4 by boosted darunavir reduces darifenacin clearance.
What to do
Do not exceed darifenacin 7.5 mg daily and monitor for anticholinergic toxicity. Consider an alternative bladder agent.
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?
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Other interactions of Darifenacin
Other interactions of Darunavir
- Alfuzosin + Darunavir Contraindicated
- Avanafil + Darunavir Contraindicated
- Darunavir + Dronedarone Contraindicated
- Darunavir + Eletriptan Contraindicated
- Darunavir + Ergotamine Contraindicated
- Darunavir + Flibanserin Contraindicated
Frequently asked questions
Can I take Darifenacin with Darunavir?
MediHelp rates the interaction as major. Darifenacin and Darunavir 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. Darunavir, usually given with a booster such as ritonavir or cobicistat, strongly inhibits CYP3A4 and can substantially raise darifenacin levels. This increases the risk of anticholinergic toxicity.
How serious is the interaction between Darifenacin and Darunavir?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not exceed darifenacin 7.5 mg daily and monitor for anticholinergic toxicity. Consider an alternative bladder agent.
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.
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