Drug interactions
Darifenacin + Ketoconazole
Severity: Major
Darifenacin and Ketoconazole: 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
Ketoconazole is a strong CYP3A4 inhibitor and substantially raises darifenacin levels. Anticholinergic adverse effects are more likely.
What this interaction means in plain words
Darifenacin and Ketoconazole 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; Ketoconazole belongs to Anti Fungals.
Why it happens
Strong CYP3A4 inhibition by ketoconazole reduces darifenacin metabolism.
What to do
Avoid if possible; otherwise limit darifenacin to 7.5 mg daily and monitor for anticholinergic effects.
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 Ketoconazole
- Alfuzosin + Ketoconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Avanafil + Ketoconazole Contraindicated
- Conivaptan + Ketoconazole Contraindicated
- Dihydroergotamine intranasal + Ketoconazole Contraindicated
- Dihydroergotamine + Ketoconazole Contraindicated
Frequently asked questions
Can I take Darifenacin with Ketoconazole?
MediHelp rates the interaction as major. Darifenacin and Ketoconazole 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. Ketoconazole is a strong CYP3A4 inhibitor and substantially raises darifenacin levels. Anticholinergic adverse effects are more likely.
How serious is the interaction between Darifenacin and Ketoconazole?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid if possible; otherwise limit darifenacin to 7.5 mg daily and monitor for anticholinergic effects.
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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