<p>Ketoconazole interacts with 14-&alpha;-sterol demethylase, a cytochrome P-450 enzyme necessary for the conversion of lanosterol to ergosterol.&nbsp;This results in inhibition of ergosterol synthesis and increased fungal cellular permeability due to reduced amounts of ergosterol present in the fungal cell membrane. This metabolic inhibition also results in accumulation of 14&alpha;-methyl-3,6-diol, a toxic metabolite. The increase in membrane fluidity is also thought to produce impairment of membrane-bound enzyme systems as components become less closely packed.</p>