Which antibiotics are safe for a breastfeeding mother to use?

Safe Antibiotics for Breastfeeding Mothers

Amoxicillin and amoxicillin/clavulanic acid are the gold standard first-line antibiotics for breastfeeding mothers, with the strongest safety evidence and classified as "compatible" with breastfeeding by the American Academy of Pediatrics. 1

First-Line Safe Antibiotics

Beta-Lactams (Safest Options)

• Amoxicillin is classified as "compatible" with breastfeeding—the highest safety designation—and represents the primary choice for most bacterial infections 2, 1
• Amoxicillin/clavulanic acid (Augmentin) is FDA Category B and explicitly recommended by the American Academy of Dermatology as safe and effective during breastfeeding 2, 1
• Cephalosporins (cephalexin, ceftriaxone, cefixime, ceftazidime) are all classified as "compatible" and serve as excellent alternatives, particularly for penicillin-allergic patients 2, 1, 3

Macrolides (Probably Safe)

• Azithromycin is classified as "probably safe" and can be used as an alternative for penicillin-allergic patients, but should be avoided during the first 13 days postpartum due to a very low risk of infantile hypertrophic pyloric stenosis 2, 1
• Erythromycin is suggested as safe, particularly for penicillin-allergic mothers 2, 1

Other Safe Options

• Metronidazole is considered safe during breastfeeding and provides excellent anaerobic coverage when needed 2, 1
• Rifampin can be used with an approach similar to other patient populations 2

Antibiotics Requiring Caution

Use Only When Specifically Indicated

• Clindamycin (oral) should be used with caution as it may increase the risk of GI side effects in the infant, including diarrhea, candidiasis, or rarely antibiotic-associated colitis 2, 1, 4

  • The FDA drug label confirms clindamycin appears in breast milk at concentrations of 0.5 to 3.8 mcg/mL and states that while breastfeeding need not be discontinued, an alternate drug may be preferred 4
  • Topical clindamycin has significantly lower systemic absorption and is safer than oral formulations if clindamycin is specifically indicated 2

• Doxycycline should be limited to a maximum of 3 weeks without repeating courses, and only used when no suitable alternative exists, due to risk of tooth discoloration and bone growth suppression 2, 1, 3

Antibiotics to Avoid

• Fluoroquinolones (ciprofloxacin, levofloxacin) should not be used as first-line treatment due to risk of cartilage damage; if absolutely necessary, ciprofloxacin is the preferred fluoroquinolone with the lowest breast milk concentration 2, 1
• Aminoglycosides should be avoided due to risk of ototoxicity and nephrotoxicity in the infant 1
• Co-trimoxazole should be avoided in premature infants, jaundiced babies, or those with G6PD deficiency due to risk of kernicterus 2, 1, 3

Clinical Decision Algorithm

Step 1: Start with amoxicillin or amoxicillin/clavulanic acid as first-line therapy for most infections unless contraindicated 2, 1, 3

Step 2: If penicillin allergy exists, use cephalosporins (cephalexin, ceftriaxone) as safe alternatives, or azithromycin/erythromycin if needed (but avoid azithromycin in first 13 days postpartum) 2, 1, 3

Step 3: For infections requiring anaerobic coverage, add metronidazole to the regimen 2, 1

Step 4: Reserve clindamycin and doxycycline only when specifically indicated and no safer alternative exists 2, 1

Essential Monitoring Considerations

• All breastfed infants should be monitored for gastrointestinal effects (diarrhea, gastroenteritis) due to alteration of intestinal flora 2, 1, 3
• Watch for changes in stool pattern or consistency, particularly with amoxicillin/clavulanic acid 3
• Monitor for candidiasis (thrush, diaper rash), especially with clindamycin use 2, 4
• Antibiotics in breast milk could potentially cause falsely negative cultures if the infant develops fever requiring evaluation 2, 1
• The small amounts of antibiotic in breast milk should not be considered therapeutic for the infant—if the baby develops an infection, they require their own appropriate dosing 2

Common Pitfalls to Avoid

• Do not discontinue breastfeeding unnecessarily—most antibiotics used for common infections are compatible with continued nursing 3
• Do not use oral clindamycin as first-line therapy when safer alternatives like amoxicillin/clavulanic acid are available 2
• Do not prescribe doxycycline as first-line therapy given the availability of safer alternatives 2
• Do not use amoxicillin/clavulanic acid in women at risk of pre-term delivery due to very low risk of necrotizing enterocolitis, though it remains safe for postpartum breastfeeding after term delivery 2