Azithromycin Safety During Breastfeeding
Yes, azithromycin is safe to take while breastfeeding. Azithromycin is classified as "probably safe" during breastfeeding by the European Respiratory Society/Thoracic Society of Australia and New Zealand guidelines, and is FDA Pregnancy Category B 1, 2.
Key Safety Information
Azithromycin can be used throughout breastfeeding with minimal risk to the infant. The drug is distributed into breast milk, but adverse effects in breastfed infants are rare and comparable to other commonly used antibiotics 1, 3.
Timing Considerations
- Ideally avoid azithromycin during the first 13 days postpartum if alternatives are available, as there is a very low risk of hypertrophic pyloric stenosis in infants exposed to macrolides during the first 13 days of breastfeeding 2.
- After 2 weeks postpartum, this risk does not persist, making azithromycin fully safe for use 2.
Expected Infant Effects
- Monitor breastfed infants for minor gastrointestinal effects including diarrhea, rash, loss of appetite, or somnolence, though these occur in only about 12.7% of exposed infants 3.
- These side effects are comparable to those seen with amoxicillin exposure (8.3% adverse reaction rate), indicating azithromycin is as safe as first-line antibiotics 3.
- Alteration of intestinal flora may occur, but serious adverse events are rare 2.
Clinical Decision Algorithm
- If infant is >2 weeks old: Use azithromycin without hesitation 2
- If infant is <13 days old: Consider amoxicillin or cephalosporins as first-line alternatives if clinically appropriate 2, 4
- If azithromycin is specifically indicated in a newborn <13 days: The benefits typically outweigh the very low risk of pyloric stenosis; monitor infant for projectile vomiting 2, 3
Important Caveats
- Antibiotics in breast milk could potentially cause falsely negative cultures if the breastfed infant develops a fever requiring evaluation 2.
- Continue breastfeeding during treatment—do not interrupt nursing when taking azithromycin 2.
- The standard adult dosing is 500 mg on day 1, followed by 250 mg daily on days 2-5 1.