Terconazole is an antifungal drug used to treat vaginal yeast infection. Terconazole may exert its antifungal activity by disrupting normal fungal cell membrane permeability. Terconazole and other triazole antifungal agents inhibit cytochrome P450 "14-alpha-demethylase" in susceptible fungi, which leads to the accumulation of lanosterol and other methylated sterols and a decrease in ergosterol concentration. Depletion of ergosterol in the membrane disrupts the structure and function of the fungal cell leading to a decrease or inhibition of fungal growth. During controlled clinical studies conducted in the United States, 521 patients with vulvovaginal candidiasis were treated with terconazole 0.4% vaginal cream. Based on comparative analyses with placebo, the adverse experiences considered most likely related to terconazole 0.4% vaginal cream were a headache and body pain. Fever and chills, vulvovaginal burning, itching, and irritation have also been reported. The adverse drug experience on terconazole most frequently causing discontinuation was vulvovaginal itching.