Drug interactions
ketoconazole + rifampin
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
Rifampin markedly reduces ketoconazole exposure via enzyme induction, risking antifungal failure; both agents can injure the liver.
Mechanism of action
Rifampin is a strong inducer of CYP3A and P-gp → ↓ ketoconazole plasma concentrations; additive hepatotoxicity risk.
Clinical management
Avoid coadministration. Use an alternative antifungal not highly dependent on CYP3A or a non-rifampin regimen. If unavoidable, monitor for clinical failure and liver function tests closely.
Drug reference
References
- Ketoconazole Tablets (Nizoral) Prescribing Information – Drug Interactions — FDA Label
- Rifampin (Rifadin) Prescribing Information – Drug Interactions — FDA Label
- Ketoconazole: Drug interactions — Lexicomp
Frequently asked questions
Can I take ketoconazole with rifampin?
The interaction is rated: Major. Rifampin markedly reduces ketoconazole exposure via enzyme induction, risking antifungal failure; both agents can injure the liver.
How serious is the interaction between ketoconazole and rifampin?
The interaction is rated: Major. Evidence level: High.
How is the interaction between ketoconazole and rifampin managed?
Avoid coadministration. Use an alternative antifungal not highly dependent on CYP3A or a non-rifampin regimen. If unavoidable, monitor for clinical failure and liver function tests closely.
Why do ketoconazole and rifampin interact?
Rifampin is a strong inducer of CYP3A and P-gp → ↓ ketoconazole plasma concentrations; additive hepatotoxicity risk.
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