Is fluconazole (an antifungal medication) safe to use during breastfeeding?

Fluconazole is Safe During Breastfeeding

Fluconazole is safe to use during breastfeeding and is the preferred azole antifungal for nursing mothers, with breastfeeding able to continue without interruption. 1

Guideline Support

• The Infectious Diseases Society of America (IDSA) explicitly recommends that breastfeeding mothers can safely continue nursing while taking fluconazole without any need to interrupt breastfeeding 1

• The American Academy of Pediatrics considers fluconazole compatible with breastfeeding, providing the highest level of guideline endorsement 1

• The European Respiratory Society/Thoracic Society of Australia and New Zealand confirms that while fluconazole is present in breast milk, it appears at levels less than the neonatal dosage, and problems have not been observed in breastfed infants from mothers treated with oral fluconazole 1

Breast Milk Levels and Infant Exposure

• Following a single 150 mg dose, fluconazole appears in breast milk at low levels, with peak milk concentration of 2.61 mcg/mL occurring at 5.2 hours post-dose 2

• The estimated daily infant dose from breast milk is 0.39 mg/kg/day, which represents only 13% of the recommended pediatric maintenance dose (3 mg/kg/day) for oropharyngeal candidiasis 2

• This minimal exposure level provides reassurance that therapeutic maternal doses result in subtherapeutic infant exposure 2

Clinical Experience with Various Dosing Regimens

• Single 150 mg doses for vaginal candidiasis are standard and safe during lactation 1

• Higher doses for breast/nipple thrush can be used without interrupting breastfeeding, as the amount excreted in breast milk remains well below therapeutic infant doses even with maternal high-dose regimens 1

• A published survey of 96 breastfeeding women treated with fluconazole 150 mg every other day (average of 7.3 capsules, range 1-29) for lactation-associated candida of the breasts reported no serious adverse reactions in infants 2, 3

• Case reports document successful treatment with fluconazole 200 mg loading dose plus 100-200 mg daily for 15-45 days for persistent breast/nipple candidiasis without adverse infant effects 4, 5

Critical Distinction: Pregnancy vs. Lactation Safety

• Do not confuse pregnancy warnings with breastfeeding safety. High-dose fluconazole (400-800 mg/day) during the first trimester of pregnancy is associated with congenital malformations, but this pregnancy concern does NOT apply to breastfeeding, where fluconazole is considered safe at all doses 1, 2

• The mechanism of teratogenicity in pregnancy (inhibition of estrogen synthesis affecting organogenesis) is irrelevant to the breastfeeding infant 2

Comparison with Other Antifungals

• Fluconazole is explicitly preferred over other systemic azoles during breastfeeding 1

• Itraconazole, posaconazole, and voriconazole should be avoided during breastfeeding due to lack of safety data and potential toxicity concerns 1, 6

• Topical options like miconazole and nystatin are also classified as "compatible" with breastfeeding and may be used for localized nipple infections 1

Practical Considerations

• No need to "pump and dump" or interrupt breastfeeding at any point during fluconazole therapy 1

• Caution should be exercised when administering fluconazole to nursing women, but this represents standard medical prudence rather than a contraindication 2

• The FDA label notes that fluconazole passes into breast milk but acknowledges the published survey showing no serious adverse reactions in breastfed infants 2