What antibiotics are safe to take during breastfeeding?

Antibiotics Safe During Breastfeeding

Most commonly used antibiotics are compatible with breastfeeding, with amoxicillin/clavulanic acid, cephalosporins, azithromycin, erythromycin, and metronidazole being the safest first-line choices. 1, 2

Preferred Safe Antibiotics

Beta-Lactams (Safest Category)

• Amoxicillin/clavulanic acid is classified as compatible with breastfeeding and recommended as a safe, effective choice 1, 2
• Cephalosporins (including cephalexin and ceftriaxone) are considered compatible with breastfeeding 1, 2, 3
• Ampicillin/sulbactam is classified as compatible, with small amounts passing into breast milk and low oral bioavailability in infants 4

Macrolides

• Azithromycin is classified as "probably safe" during breastfeeding 1, 2
• Erythromycin is suggested as safe, particularly for penicillin-allergic patients 1, 2, 3
• Clarithromycin transfers less than 2% of the maternal weight-adjusted dose into breast milk, with adverse effects comparable to amoxicillin 5

Other Safe Options

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

Antibiotics Requiring Caution or Limitation

Use With Monitoring

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

Avoid as First-Line

• Ciprofloxacin and other fluoroquinolones are classified as "possibly safe" but most clinicians avoid during lactation due to theoretical concerns about cartilage damage, though human data suggest low risk 1
• Co-trimoxazole should be avoided in premature babies, jaundiced infants, or those with G6PD deficiency 1

Critical Infant Monitoring Considerations

Timing-Specific Risks

• There is a very low risk of hypertrophic pyloric stenosis in infants exposed to macrolides (azithromycin, erythromycin, clarithromycin) during the first 13 days of breastfeeding, but this risk does not persist after 2 weeks 1, 2, 3

General Monitoring

• All breastfed infants should be monitored for gastrointestinal effects (diarrhea, altered stool patterns) due to alteration of intestinal flora 1, 2
• Antibiotics in breast milk could potentially cause falsely negative cultures if the breastfed infant develops fever requiring evaluation 1, 2

Common Pitfalls to Avoid

• Do not unnecessarily discontinue breastfeeding due to lack of accurate information about antibiotic safety 6, 7
• Avoid long-acting formulations when possible; choose drugs with short half-lives to minimize accumulation risk 8
• Time medication administration immediately following a breastfeed to minimize infant exposure at peak milk concentrations (typically 1-2 hours post-dose) 8
• The safety profile assumes healthy, full-term infants; exercise additional caution in premature infants or those with medical conditions 4

Clinical Decision Algorithm

1. First choice: Amoxicillin/clavulanic acid or cephalosporins (compatible, extensive safety data) 1, 2, 3
2. For penicillin allergy: Azithromycin or erythromycin (avoid in first 13 days if possible due to pyloric stenosis risk) 1, 2, 3
3. For anaerobic coverage: Metronidazole (safe option) 1, 2
4. Avoid doxycycline unless no alternatives exist, then limit to 3 weeks 1, 2
5. Use clindamycin with caution and monitor infant for diarrhea 1, 2