Drug interactions
Ketoconazole + Vardenafil
Severity: Major
Ketoconazole and Vardenafil: 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 markedly increases vardenafil exposure, raising the risk of hypotension, QT prolongation and prolonged erections. Labeling restricts vardenafil doses with this strong inhibitor.
What this interaction means in plain words
Ketoconazole and Vardenafil 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; Vardenafil belongs to Genitourinary.
Why it happens
Ketoconazole is a strong CYP3A4 inhibitor that greatly reduces vardenafil clearance.
What to do
Cap vardenafil at 2.5 mg per 24 hours with ketoconazole 400 mg/day and 5 mg per 24 hours with 200 mg/day, or choose an alternative; monitor blood pressure.
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 Vardenafil
- Amyl nitrite + Vardenafil Contraindicated
- Glyceryl trinitrate pr + Vardenafil Contraindicated
- Isosorbide dinitrate + Vardenafil Contraindicated
- Isosorbide mononitrate + Vardenafil Contraindicated
- Nicorandil + Vardenafil Contraindicated
- Nitroglycerin po + Vardenafil Contraindicated
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 Vardenafil?
MediHelp rates the interaction as major. Ketoconazole and Vardenafil 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 markedly increases vardenafil exposure, raising the risk of hypotension, QT prolongation and prolonged erections. Labeling restricts vardenafil doses with this strong inhibitor.
How serious is the interaction between Ketoconazole and Vardenafil?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Cap vardenafil at 2.5 mg per 24 hours with ketoconazole 400 mg/day and 5 mg per 24 hours with 200 mg/day, or choose an alternative; monitor blood pressure.
What other medicines interact with Vardenafil?
MediHelp also lists interactions of Vardenafil with, for example, Amyl nitrite, Glyceryl trinitrate pr, Isosorbide dinitrate. The full list is on the Vardenafil page.
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