Macrobid (Nitrofurantoin) and Breastfeeding
Nitrofurantoin is generally safe to use during breastfeeding, but exercise caution in infants younger than 1 month of age due to theoretical risk of hemolytic anemia, particularly in the first week of life. 1
Safety Profile
- Only small amounts of nitrofurantoin transfer into breast milk, making it generally compatible with breastfeeding 1
- Most antibiotics, including nitrofurantoin, are considered compatible with breastfeeding and should not necessitate interruption of nursing 2
- The relative infant dose through breast milk is expected to be minimal, well below concerning thresholds 1
Age-Specific Considerations
Infants Under 1 Month Old
- There is a theoretical risk of hemolytic anemia in newborns exposed to nitrofurantoin due to glutathione instability, especially in the first days of life 1
- This risk is particularly elevated in infants with glucose-6-phosphate dehydrogenase (G6PD) deficiency 1
- Glutathione stability may be established by the eighth day of life, reducing this theoretical risk 1
- Some sources suggest avoiding nitrofurantoin in infants younger than 1 month, though this is based on theoretical rather than documented harm 1
Infants Over 1 Month Old
- Nitrofurantoin is considered safe for breastfeeding mothers with older infants 1
- No documented reports of adverse effects exist in the literature 1
Clinical Decision Algorithm
If the infant is younger than 1 month:
- Consider an alternative antibiotic as first-line if readily available 1
- If no suitable alternative exists, nitrofurantoin can still be used and is not a reason to discontinue breastfeeding 1
- Monitor the infant closely for signs of hemolysis (jaundice, pallor, poor feeding) 1
If the infant is older than 1 month:
- Use nitrofurantoin without hesitation 1
- Standard monitoring for any breastfed infant on maternal medications applies 2
Important Caveats
- Never recommend discontinuing breastfeeding unless absolutely necessary, as the benefits of breastfeeding typically outweigh theoretical medication risks 2, 3
- The lack of documented adverse events despite widespread use supports the safety profile 1
- Screen for G6PD deficiency if there is family history or ethnic predisposition, as this significantly increases hemolysis risk 1