Is Macrobid (Nitrofurantoin) safe during breastfeeding?

From the Guidelines

Macrobid (nitrofurantoin) is generally considered safe to use while breastfeeding, with only small amounts passing into breast milk, as indicated by the American Academy of Pediatrics classification as compatible with breastfeeding 1.

Key Considerations

• The typical dosage for urinary tract infections is 100 mg twice daily for 5-7 days.
• For breastfeeding mothers, it's best to take the medication immediately after nursing to minimize the amount in milk during the next feeding.
• While using Macrobid, monitor your baby for potential side effects such as diarrhea, vomiting, or rash, though these are rare.
• The medication works by killing bacteria in the urinary tract and has minimal systemic absorption, which is why it poses little risk to nursing infants.

Important Precautions

• Macrobid should be avoided in infants under one month of age and in mothers nursing premature infants due to the theoretical risk of hemolytic anemia related to immature enzyme systems.
• Always inform your healthcare provider that you are breastfeeding before starting any medication.

Relative Infant Dose

• The relative infant dose is a valuable guide to the safety of a drug taken by a breastfeeding woman, with a proportion < 10% considered the preferred option, as noted in the guideline on anaesthesia and sedation in breastfeeding women 2020 1.

Recommendations

• Based on the available evidence, Macrobid can be used safely in breastfeeding mothers, with proper precautions and monitoring.
• It is essential to follow the recommended dosage and consult with a healthcare provider before starting the medication.

From the Research

Macrobid and Breastfeeding

• Macrobid, also known as nitrofurantoin, is an antibiotic used to treat urinary tract infections.
• The safety of using Macrobid while breastfeeding has been studied, and the results are as follows:
  • A study from 2014 2 found that the use of nitrofurantoin in breastfeeding mothers is generally safe, as only small amounts transfer into the breast milk.
  • However, there is a risk of hemolytic anemia in all newborns exposed to nitrofurantoin, especially in infants with glucose-6-phosphate dehydrogenase deficiency.
  • Another study from 2022 3 reviewed reports of hemolysis associated with nitrofurantoin and found that the risk of hemolytic anemia is low, with only 42 reported cases out of at least 245 million exposures.
  • A study from 2003 4 found that the use of most antibiotics, including nitrofurantoin, is considered compatible with breastfeeding.
  • A study from 2011 5 provides an evidence-based review of medicines used for common situations and their compatibility with breastfeeding, but does not specifically mention Macrobid.
  • A study from 1990 6 discusses the risk of hemolytic reactions to nitrofurantoin in patients with glucose-6-phosphate dehydrogenase deficiency, but does not specifically address breastfeeding.

Precautions and Recommendations

• If Macrobid is prescribed to a breastfeeding mother, the infant should be monitored by their physician for signs of hemolytic anemia.
• Alternative antibiotics may be preferred for infants younger than 1 month, but if Macrobid is used, it is not a reason to avoid breastfeeding.
• The use of Macrobid during breastfeeding should be accompanied by appropriate advice and monitoring for serious adverse events, especially in regions with high prevalence of glucose-6-phosphate dehydrogenase deficiency 3.