Drug interactions
famotidine + ketoconazole
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.
Overview
Famotidine increases gastric pH, reducing oral ketoconazole absorption and exposure, risking antifungal treatment failure.
Mechanism of action
H2-receptor antagonism elevates gastric pH, decreasing dissolution and absorption of ketoconazole, which requires an acidic environment.
Clinical management
Avoid if possible. If necessary, give ketoconazole at least 2 hours before famotidine and with an acidic beverage (e.g., cola); monitor clinical response or use a non–pH-dependent antifungal.
Drug reference
References
- NIZORAL (ketoconazole) tablets label — Drug Interactions: agents that reduce gastric acidity — FDA Label
- PEPCID (famotidine) prescribing information — Drug Interactions — FDA Label
- Famotidine–Ketoconazole interaction monograph — Lexicomp
Frequently asked questions
Can I take famotidine with ketoconazole?
The interaction is rated: Moderate. Famotidine increases gastric pH, reducing oral ketoconazole absorption and exposure, risking antifungal treatment failure.
How serious is the interaction between famotidine and ketoconazole?
The interaction is rated: Moderate. Evidence level: High.
How is the interaction between famotidine and ketoconazole managed?
Avoid if possible. If necessary, give ketoconazole at least 2 hours before famotidine and with an acidic beverage (e.g., cola); monitor clinical response or use a non–pH-dependent antifungal.
Why do famotidine and ketoconazole interact?
H2-receptor antagonism elevates gastric pH, decreasing dissolution and absorption of ketoconazole, which requires an acidic environment.
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