FDA warning: Fluconazole may cause birth defects

Long-term use of high doses of fluconazole (Diflucan) during pregnancy may be associated with birth defects, according to the FDA.

The agency issued a warning stating that chronic use of fluconazole in doses of 400 mg to 800 mg per day during the first trimester of pregnancy may be associated with a "rare and distinct set of birth defects." As a result, FDA changed the category of the drug in that dosage from C to D, meaning that positive evidence exists regarding human fetal risk based on human data, but that potential benefits of using the drug in pregnant women with serious or life-threatening conditions may outweigh the risks. The agency noted that a single low dose, used frequently to treat vaginal candidiasis, remains category C.

Birth defects noted include abnormal head, skull, and facial defects; cleft palate and/or lip; bowing of the thigh bones; thin ribs; long bones; muscle weakness; joint deformities; and congenital heart disease at birth. The information came from 5 case studies. Four of the 5 women took fluconazole to treat meningitis; the remaining woman was HIV-positive and used chronic, high doses of fluconazole to treat a vaginal yeast infection.

FDA also encourages healthcare professionals and patients to report adverse events or side effects related to the use of fluconazole to the FDA's MedWatch Safety Information and Adverse Event Reporting Program by completing and submitting the report online at http://www.fda.gov/MedWatch/report.htm; by downloading the form from http://www.fda.gov/Safety/MedWatch/HowToReport/DownloadForms/default.htm; or by calling 1-800-332-1088 to request a reporting form. Completed forms should be returned to the address on the preaddressed form or submitted by fax to 1-800-FDA-0178.

Diflucan (fluconazole): Drug Safety Communication-Long-term, high-dose use during pregnancy may be associated with birth defects [news release]. US Food and Drug Administration; August 3, 2011. http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm266468.htm. Accessed August 7, 2011.