Following vaginal administration of butoconazole nitrate vaginal cream, 2% to 3 women, 1.7% (range 1.3 - 2.2%) of the dose was absorbed on average. Peak plasma levels (13.6 - 18.6 ng radioequivalents/mL of plasma) of the drug and its metabolites are attained between 12 and 24 hours after vaginal administration.

Microbiology

The exact mechanism of the antifungal action of butoconazole nitrate is unknown; however, it is presumed to function as other imidazole derivatives via inhibition of steroid synthesis. lmidazoles generally inhibit the conversion of lanosterol to ergosterol, resulting in a change in fungal cell membrane lipid composition. This structural change alters cell permeability and, ultimately, results in the osmotic disruption or growth inhibition of the fungal cell.

Butoconazole nitrate is an imidazole derivative that has fungicidal activity in vitro against Candida spp. and has been demonstrated to be clinically effective against vaginal infections due to Candida albicans. Candida albicans has been identified as the predominant species responsible for vulvovaginal candidiasis.

Clinical Studies

Vulvovaginal Candidiasis: Two studies were conducted that compared 2% butoconazole nitrate cream with clotrimazole tablets. There were 322 enrolled patients, 161 received 2.0% butoconazole vaginal cream and 161 patients inserted the 500-mg clotrimazole vaginal tablet. At the second follow-up visit (30 days post-therapy), 118 patients in the butoconazole group and 116 in the clotrimazole group were evaluable for efficacy analysis, respectively. All of these patients had infection caused by Candida albicans.

The efficacy of the study drugs was assessed by evaluating clinical, mycologic and therapeutic cure rates, which are summarized in Table 1. The therapeutic cure is defined by a complete resolution of signs and symptoms of vaginal candidiasis (clinical cure) along with a negative KOH examination and negative culture for Candida spp. (microbiologic eradication) at the long term follow-up. The therapeutic cure rate was 67% in the butoconazole group and 61% in the clotrimazole group.

Table 1

Last reviewed on RxList: 7/17/2008
This monograph has been modified to include the generic and brand name in many instances.