Drug interactions
Ketoconazole + Solifenacin
Severity: Major
Ketoconazole and Solifenacin: 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 strongly inhibits CYP3A4, the main metabolic pathway of solifenacin, and substantially increases its exposure. This raises the risk of antimuscarinic adverse effects and QT prolongation.
What this interaction means in plain words
Ketoconazole and Solifenacin 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 belongs to Anti Fungals; Solifenacin belongs to Genitourinary.
Why it happens
Strong CYP3A4 inhibition reducing solifenacin clearance.
What to do
Limit solifenacin to 5 mg once daily during concurrent use of ketoconazole or other strong CYP3A4 inhibitors. Monitor for anticholinergic effects and the ECG in patients with QT risk factors.
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 Solifenacin
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 Ketoconazole with Solifenacin?
MediHelp rates the interaction as major. Ketoconazole and Solifenacin 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 strongly inhibits CYP3A4, the main metabolic pathway of solifenacin, and substantially increases its exposure. This raises the risk of antimuscarinic adverse effects and QT prolongation.
How serious is the interaction between Ketoconazole and Solifenacin?
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 solifenacin to 5 mg once daily during concurrent use of ketoconazole or other strong CYP3A4 inhibitors. Monitor for anticholinergic effects and the ECG in patients with QT risk factors.
What other medicines interact with Solifenacin?
MediHelp also lists interactions of Solifenacin with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Solifenacin page.
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