BUTOCONAZOLE

Fetal Risk Summary

Butoconazole, an imidazole derivative, is available as a topical cream for the treatment of vaginal fungal infections. The agent is teratogenic in some animal species, but only when large oral doses are administered (1).

An average 5.5% of a vaginal dose is absorbed systemically with peak plasma levels appearing at about 24 hours (1). No data are available on the placental trans fer of this agent, but the low molecular weight (475) indicates that transfer to the fetus probably occurs.

No published reports of butoconazole use in the 1st trimester have been located. However, butoconazole is one of several agents that have been approved for 2nd and 3rd trimester use in the treatment of vulvovaginal mycotic infections (2,3 and 4). Therapy for 6 days is recommended if this antifungal is used.

In a surveillance study of Michigan Medicaid recipients involving 229,101 completed pregnancies conducted between 1985 and 1992, 444 newborns had been exposed to vaginal butoconazole during the 1st trimester (F. Rosa, personal communication, FDA, 1993). A total of 16 (3.6%) major birth defects were observed (17 expected). Specific data were available for six defect categories, including (observed/expected) 4/4 cardiovascular defects, 0/1 oral clefts, 1/0 spina bifida, 0/0.5 polydactyly, 0/1 limb reduction defects, and 0/1 hypospadias. These data do not support an association between the vaginal use of the drug and congenital defects.

Breast Feeding Summary

No data are available.

References

1. Product information. Femstat. Syntex, 1993.
2. Weisberg M. Treatment of vaginal candidiasis in pregnant women. Clin Ther 1986;8:563–7.
3. Hagler L, Brett L. Treatment of vaginal candidiasis in pregnant women. Clin Ther 1987;9:559–60.
4. Weisberg M. Treatment of vaginal candidiasis in pregnant women. Clin Ther 1987;9:561.