isavuconazole + ketoconazole

Isavuconazole + ketoconazole is a combination of two antifungal agents, both classified as triazole antifungals. **Isavuconazole** is the active moiety of the prodrug isavuconazonium sulfate and inhibits the cytochrome P450–dependent enzyme lanosterol 14α-demethylase, blocking ergosterol synthesis and impairing fungal cell membrane integrity, leading to cell death[2][4]. **Ketoconazole** operates via the same mechanism, inhibiting fungal lanosterol 14α-demethylase and also acts as a strong inhibitor of CYP3A4 in humans. When coadministered, **ketoconazole significantly increases exposure to isavuconazole** via potent inhibition of isavuconazole's CYP3A4 metabolism[1][3][5]. This combination is not formulated or marketed as a fixed-dose product, but may occur as a result of concomitant use. Isavuconazole is primarily used for invasive aspergillosis and mucormycosis; ketoconazole (oral) is generally reserved for non-systemic fungal infections due to toxicity risks.

Brand names

Cresemba (isavuconazole)Nizoral (ketoconazole)

Other names

isavuconazonium sulfate (prodrug of isavuconazole)