Is Macrobid safe while breastfeeding?

What does the evidence say about Macrobid while breastfeeding?

1. Nitrofurantoin was undetectable, under 2 mg/L, in milk samples from postpartum women taking 100 mg four times a day, and an exclusively breastfed baby would get an estimated 0.2 mg/kg daily, about 6 percent of the weight-adjusted maternal dose. 1
2. Giving nitrofurantoin directly to infants younger than 1 month old, or to any infant with G6PD deficiency, is contraindicated because of a hemolysis risk, and the highest-risk window for a full-term newborn without G6PD deficiency may be as short as the first 8 days after birth. 1
3. A relative infant dose of about 6 percent sits well under the roughly 10 percent level generally considered reassuring for a medication taken while nursing, and once a baby is past 8 days old and doesn't have G6PD deficiency, nitrofurantoin use is not considered a reason to avoid breastfeeding, though the baby should still be monitored. 2
4. In a small report of 6 nursing mothers taking nitrofurantoin, 2 reported diarrhea in their infants and no rashes or yeast infections were reported; the benefits of managing the infection and continuing to breastfeed are generally weighed against this small, reported risk. 3
5. Nitrofurantoin is typically dosed at 100 mg twice daily for 5 to 7 days for an uncomplicated urinary tract infection, concentrates in the urinary tract while keeping blood levels low, and is specifically avoided in pregnant women at term (38 to 42 weeks) as well as during labor and delivery. 4

How Macrobid changes by nursing stage

• Early weeks. If your baby is younger than 8 days old, providers generally prefer a different antibiotic for a UTI, since a full-term newborn's natural defense against hemolysis hasn't stabilized yet and nitrofurantoin is contraindicated for infants under 1 month with G6PD deficiency.
• Established nursing. Once your baby is past 8 days old and doesn't have G6PD deficiency, nitrofurantoin while nursing is not expected to cause problems: an exclusively breastfed baby gets roughly 6 percent of the weight-adjusted maternal dose, well under the roughly 10 percent threshold providers watch for.
• Weaning. Watch your baby for diarrhea while you're taking it, since that was the main side effect reported in a small group of nursing mothers on nitrofurantoin. Confirm whether your baby has G6PD deficiency if that hasn't been checked, particularly if your family background raises the chances of it.