What antibiotics are safe to use during breastfeeding?

Antibiotics Safe During Breastfeeding

Most commonly used antibiotics are safe during breastfeeding, with penicillins, cephalosporins, and macrolides being preferred first-line agents, while doxycycline should be limited to 3 weeks maximum and clindamycin used with caution due to infant GI side effects. 1

Recommended Safe Antibiotics

Beta-Lactams (First-Line Options)

• Amoxicillin/clavulanic acid is explicitly recommended as a safe and effective choice during breastfeeding by the American Academy of Dermatology 1, 2, 3
• Penicillins and cephalosporins are considered compatible with breastfeeding and should be used as first-line options when appropriate 3, 4
• Cephalosporins (including cephalexin and ceftriaxone) have minimal transfer to breast milk with limited impact on nursing infants 2, 3
• Ampicillin/sulbactam is classified as compatible with breastfeeding, though small amounts pass into breast milk with low oral bioavailability in infants 5

Macrolides

• Azithromycin is classified as "probably safe" during breastfeeding by the European Respiratory Society 2, 3
• Erythromycin is suggested as safe, particularly for penicillin-allergic patients 1, 2
• Clarithromycin and its active metabolite transfer to breast milk at less than 2% of the maternal weight-adjusted dose, with adverse effects (rash, diarrhea, loss of appetite, somnolence) comparable to amoxicillin 6
• 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 2

Other Safe Options

• Metronidazole is suggested as safe during breastfeeding 1, 2, 3
• Rifampin can be used with an approach similar to other patient populations 1, 2

Antibiotics Requiring Caution

Use With Monitoring

• Clindamycin should be used with caution as it may increase the risk of GI side effects in the infant 1, 3
• Doxycycline use should be limited to 3 weeks maximum without repeating courses; use only if no suitable alternative is available 1, 2

Special Populations Requiring Avoidance

• Trimethoprim-sulfamethoxazole should be avoided in premature babies, jaundiced infants, or those with G6PD deficiency 2
• Trimethoprim-sulfamethoxazole levels in breast milk are approximately 2-5% of the recommended daily dose for infants over 2 months, with caution needed for jaundiced, ill, stressed, or premature infants due to risk of bilirubin displacement and kernicterus 7

Monitoring Considerations

Infant Surveillance

• All breastfed infants should be monitored for gastrointestinal effects due to alteration of intestinal flora 2
• Antibiotics in breast milk could potentially cause falsely negative cultures if the breastfed infant develops fever requiring evaluation 2
• The most common potential side effect across antibiotic classes is mild gastrointestinal disturbance in the infant 5

Important Assumptions

• The safety profile of antibiotics during breastfeeding assumes full-term, healthy infants, standard recommended doses and durations, and exclusive breastfeeding 2
• Additional caution may be warranted in premature infants or those with other medical conditions 5

Clinical Decision Algorithm

Step 1: Choose beta-lactams (penicillins or cephalosporins) as first-line agents when clinically appropriate 3, 4

Step 2: For penicillin-allergic patients, use macrolides (azithromycin or erythromycin), avoiding the first 13 days postpartum if possible 2, 3

Step 3: If clindamycin is necessary, counsel parents about potential infant GI side effects and monitor closely 1, 3

Step 4: Reserve doxycycline for situations with no suitable alternatives, limiting to 3 weeks without repeating courses 1, 2

Step 5: Use the lowest effective dose for the shortest duration needed to minimize infant exposure 5

Common Pitfalls to Avoid

• Do not unnecessarily discontinue breastfeeding when safe antibiotic alternatives exist 8, 4
• Do not use tetracyclines beyond 3 weeks or in repeated courses 1, 2
• Do not prescribe trimethoprim-sulfamethoxazole to mothers of jaundiced, premature, or G6PD-deficient infants 2, 7
• Do not assume all antibiotics are unsafe—most commonly used antibiotics are compatible with breastfeeding 8, 4