Ketoconazole (R-41400) is an imidazole antifungal agent with broad-spectrum antifungal activity that primarily acts by inhibiting the biosynthesis of ergosterol in the fungal cell membrane. Ketoconazole inhibits the fungal cytochrome P450-dependent enzyme lanosterol 14alpha-demethylase (CYP51), thereby blocking the conversion of lanosterol to ergosterol. This leads to damage to the cell membrane structure and permeability, consequently inhibiting fungal growth and producing an antifungal effect. In addition, ketoconazole is a non-selective cytochrome P450 (CYP) inhibitor, specifically inhibiting drug-metabolizing enzymes such as human CYP3A4. In terms of endocrinology, ketoconazole also inhibits various enzymes involved in steroid synthesis (CYP17A1, CYP11A1).
