Safety of Metronidazole and Fluconazole During Breastfeeding

Fluconazole (Diflucan) – Compatibility with Breastfeeding

The American Academy of Pediatrics and the Infectious Diseases Society of America classify fluconazole as compatible with breastfeeding, indicating it can be used at any dose without interrupting nursing. 2
Fluconazole is detectable in breast milk at concentrations lower than the therapeutic neonatal dose, and no adverse effects have been reported in breast‑fed infants. 2
Even when mothers receive high‑dose regimens (400–800 mg/day), the amount excreted into milk remains well below doses required for infant therapy. 2
High‑dose fluconazole during the first trimester of pregnancy is linked to congenital malformations, but this risk does not apply to the lactation period; fluconazole remains safe for nursing infants at all doses. 2
A single 150 mg dose for vaginal candidiasis is considered safe for the breastfeeding mother and infant. 2
For breast or nipple thrush, a regimen of 100–200 mg daily for 7–14 days can be used without stopping breastfeeding. 2
For recurrent vaginal candidiasis, 150 mg administered every 72 hours for three doses is compatible with continued nursing. 2

With the standard dosing schedule of 400 mg three times daily, breastfeeding may continue uninterrupted; clinical studies have shown no serious infant reactions at the resulting plasma concentrations. 1
After a single high‑dose oral regimen of 2 g metronidazole, breastfeeding should be paused for 12–24 hours to markedly reduce infant exposure. 1
The only circumstance that requires temporary cessation of nursing is the administration of a single 2 g dose; standard multi‑dose regimens do not necessitate breastfeeding interruption. 1