MajorSystemic antimycotics. Imidazole derivatives×Antituberculous antibiotic
Updated · Methodology
Mechanism
Dual mechanism. Rifampicin strongly induces CYP3A4, which partly metabolises ketoconazole. Ketoconazole plasma levels fall by 50–80%; antifungal efficacy is lost.
Symptoms
Recurrence of mycosis symptoms: ongoing fever, skin or mucosal lesions; in immunocompromised patients, risk of systemic mycosis progression.
Management
The combination is not prescribed. Alternative antifungal during anti-TB therapy: echinocandins (micafungin, caspofungin; resistant to CYP3A4 induction) or terbinafine for dermatophytosis.
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Sources
- FDA: Rifampin capsule (Ani Pharmaceuticals, Inc.) – Prescribing Information (2010)– ; DailyMed setid b389b1a3-672f-47e3-916c-4a9c044b211b
- AEMPS: Ficha técnica: Rifampicina (nº registro 49034), sección 4.5 (2026)– AEMPS, CIMA, nº registro 49034, revisión 08/2026, sección 4.5