Is azithromycin (Zithromax) safe to use while breastfeeding?

Azithromycin Safety During Breastfeeding

Azithromycin is considered safe to use while breastfeeding, with minimal risk to the infant. 1

Safety Profile

• Azithromycin is classified as "probably safe" during breastfeeding according to the European Respiratory Society/Thoracic Society of Australia and New Zealand guidelines 1
• The FDA label notes that "it is not known whether azithromycin is excreted in human milk" and recommends caution when administered to nursing women 2
• Macrolides, including azithromycin, are generally considered compatible with breastfeeding with limited transfer into breast milk 3, 4

Specific Considerations

• There is a very low risk of hypertrophic pyloric stenosis in infants exposed to macrolides during the first 13 days of breastfeeding, but this risk does not persist after 2 weeks 1
• Breastfed infants should be monitored for potential mild gastrointestinal effects due to alteration of intestinal flora 1, 4
• The presence of antibiotics in breast milk could potentially cause falsely negative cultures if the breastfed infant develops a fever requiring evaluation 1

Dosing Considerations

• Standard therapeutic doses of azithromycin can be used while breastfeeding 4
• The percentage of maternal dose that reaches the infant through breast milk is generally small and unlikely to cause significant adverse effects 5, 6
• A case report has documented the presence of azithromycin in breast milk, showing a time-dependent profile rather than accumulation 7

Clinical Context

• Most medications, including antibiotics like azithromycin, can be used safely during breastfeeding at recommended doses 6, 8
• The benefits of continuing breastfeeding generally outweigh the minimal risks associated with azithromycin exposure through breast milk 6
• In almost all instances with medications like azithromycin, mothers should be advised to continue breastfeeding rather than interrupting it 6

Alternative Antibiotics

• If there are concerns about azithromycin, amoxicillin/clavulanic acid is classified as compatible with breastfeeding according to FDA (Category B) and clinical practice guidelines 9
• Cephalosporins are also considered "compatible" with breastfeeding and may be suitable alternatives 1

Bottom Line

• Azithromycin can be safely used during breastfeeding with minimal risk to the infant 1, 4
• The mother should be encouraged to continue breastfeeding while taking azithromycin 6
• Monitor the infant for potential mild gastrointestinal effects, though these are uncommon 1