Ketoconazole-d
3 is intended for use as an internal standard for the quantification of ketoconazole by GC- or LC-MS. Ketoconazole is a broad-spectrum triazole antifungal agent that has activity against
C. albicans,
C. krusei,
C. tropicalis,
C. glabrata,
C. parapsilosis,
C. neoformans, and
A. fumigatus strains (IC
50s = 0.031-8 μg/ml).
1 It inhibits the fungal cytochrome P450 (CYP) isoform CYP51, also known as lanosterol 14α-demethylase, which arrests ergosterol biosynthesis at the fungal membrane. Ketoconazole also inhibits human CYP3A4 (IC
50 = 0.54 μM). Formulations containing ketoconazole have been used in the treatment of fungal infections.