Safety in Lactation: Metronidazole

Metronidazole is considered a drug of low toxicity and is compatible with breastfeeding. Even though levels in breast milk are comparatively higher compared to some other drugs, the levels reported are far less than those used therapeutically in infants.
When systemic treatment is required the oral route is preferred in the mother as this produces slightly lower levels in milk.
Monitor infant for gastro-intestinal disturbances and oral candida infection, especially if used in high doses, although these effects are unlikely to occur.
Choice of drug and alternatives may be directed by local antimicrobial policy.