A synthetic derivative of phenylpiperazine with broad antifungal properties and potential antineoplastic activity. Ketoconazole inhibits sterol 14-a-dimethylase, a microsomal cytochrome P450-dependent enzyme, thereby disrupting synthesis of ergosterol, an important component of the fungal cell wall. or A drug that treats infection caused by a fungus. It is also used as a treatment for prostate cancer because it can block the production of male sex hormones.