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Butoconazole topical Pregnancy and Breastfeeding Warnings

Medically reviewed by Last updated on Oct 5, 2022.

Butoconazole topical is also known as: Femstat 3, Femstat Prefill, Gynazole-1, Mycelex-3

Butoconazole topical Pregnancy Warnings

Animal studies have failed to reveal evidence of teratogenicity; resorption rate increased and litter size decreased in pregnant rats administered 6 mg/kg/day intravaginally during organogenesis (dose represents 130- to 353-fold margin of safety based on serum levels in rats after intravaginal administration compared to serum levels in humans after intravaginal use at recommended therapeutic dose). No adverse effect observed when pregnant rats were administered up to 50 mg/kg/day orally throughout organogenesis (5 times human dose based on mg/m2), but daily oral doses of 100, 300, or 750 mg/kg/day (10, 30, or 75 times human dose based on mg/m2) resulted in fetal malformations (abdominal wall defects, cleft palate) as well as maternal toxicity; no adverse effects on litters were observed in rabbits, even at maternally toxic doses (e.g., 150 mg/kg, 24 times human dose based on mg/m2). This drug caused dystocia in rats, but not rabbits, when administered through parturition. There are no controlled data in human pregnancy; however, use during the second and third trimester has been documented with no adverse fetal outcome.

In a review of 229,101 deliveries to Michigan Medicaid patients, 444 first-trimester exposures to this drug and 2450 exposures any time during pregnancy were recorded. A total of 16 birth defects were reported with first trimester exposure (17 expected) and included (observed/expected) 4/4 cardiovascular defects and 1 spina bifida. These data do not support an association between use of this drug and birth defects (written communication, Franz Rosa, MD, Food and Drug Administration, 1994).

AU TGA pregnancy category B3: Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed. Studies in animals have shown evidence of an increased occurrence of fetal damage, the significance of which is considered uncertain in humans.

US FDA pregnancy category C: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.

This drug should be used during pregnancy only if the benefit outweighs the risk to the fetus.

AU TGA pregnancy category: B3
US FDA pregnancy category: C

See references

Butoconazole topical Breastfeeding Warnings

Caution is recommended; according to some experts, other antifungal agents may be preferred, particularly while breastfeeding newborn or preterm infants.

Excreted into human milk: Unknown
Excreted into animal milk: Yes

-This drug has not been studied during breastfeeding.
-The effects in the nursing infant are unknown; about 5.5% of a vaginal dose is absorbed and the plasma half-life is 21 to 24 hours.

See references

References for pregnancy information

  1. "Product Information. Femstat (butoconazole topical)." Syntex Laboratories Inc (2022):
  2. TGA. Therapeutic Goods Administration. Australian Drug Evaluation Committee "Prescribing medicines in pregnancy: an Australian categorisation of risk of drug use in pregancy." (2007):

References for breastfeeding information

  1. "Product Information. Femstat (butoconazole topical)." Syntex Laboratories Inc (2022):
  2. United States National Library of Medicine "Toxnet. Toxicology Data Network." (2013):

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.