Drug interactions
Ketoconazole + Lansoprazole
Severity: Major
Ketoconazole and Lansoprazole: 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 needs gastric acid for dissolution, so lansoprazole can substantially reduce its absorption and cause antifungal failure.
What this interaction means in plain words
Ketoconazole and Lansoprazole 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; Lansoprazole belongs to Gastrointestinal Tract.
Why it happens
Raised gastric pH reduces dissolution and absorption of ketoconazole.
What to do
Avoid the combination where possible and consider fluconazole or another non-acid-dependent antifungal. If unavoidable, monitor clinical response.
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 Lansoprazole
- Lansoprazole + Mavacamten Contraindicated
- Lansoprazole + Rilpivirine Contraindicated
- Acalabrutinib + Lansoprazole Major
- Atazanavir + Lansoprazole Major
- Dacomitinib + Lansoprazole Major
- Dasatinib + Lansoprazole Major
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 Lansoprazole?
MediHelp rates the interaction as major. Ketoconazole and Lansoprazole 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 needs gastric acid for dissolution, so lansoprazole can substantially reduce its absorption and cause antifungal failure.
How serious is the interaction between Ketoconazole and Lansoprazole?
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 the combination where possible and consider fluconazole or another non-acid-dependent antifungal. If unavoidable, monitor clinical response.
What other medicines interact with Lansoprazole?
MediHelp also lists interactions of Lansoprazole with, for example, Mavacamten, Rilpivirine, Acalabrutinib. The full list is on the Lansoprazole page.
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