Safe Antibiotics During Breastfeeding
Most commonly used antibiotics including penicillins, cephalosporins, and macrolides are safe during breastfeeding, with amoxicillin/clavulanic acid, cephalexin, azithromycin, and erythromycin being preferred first-line options. 1, 2, 3
Recommended Safe Antibiotics
Penicillins and Beta-Lactams (Safest Options)
- Amoxicillin/clavulanic acid is strongly recommended as a safe and effective choice during breastfeeding, classified as FDA Category B and compatible with breastfeeding by the American Academy of Dermatology 1, 2
- Amoxicillin alone is considered the gold standard with "good data" supporting no teratogenic potential and compatibility with breastfeeding 4, 5
- Cephalosporins (cephalexin, cefuroxime, ceftriaxone) are classified as "compatible" with breastfeeding and are safe first-line options 3, 6, 7
Macrolides
- Azithromycin and erythromycin are suggested as safe alternatives, particularly for penicillin-allergic patients 1, 3
- Azithromycin is classified as "probably safe" by ERS/TSANZ guidelines 3
- There is a very low risk of hypertrophic pyloric stenosis only during the first 13 days of breastfeeding, which does not persist after 2 weeks 3, 6
Other Safe Options
- Rifampin can be used with an approach similar to other patient populations 1
- Metronidazole is suggested as safe during breastfeeding 1, 4
- Trimethoprim-sulfamethoxazole and vancomycin appear relatively safe in the minimal quantities ingested through breast milk 8, 5
Antibiotics Requiring Caution
Clindamycin - Use With Monitoring
- Exercise caution with oral clindamycin as it may increase the risk of GI side effects in the infant 1
- The FDA label states clindamycin appears in breast milk at 0.5-3.8 mcg/mL and has potential to cause adverse effects on the infant's gastrointestinal flora 9
- Monitor the breastfed infant for diarrhea, candidiasis (thrush, diaper rash), or blood in stool indicating possible antibiotic-associated colitis 9
- Despite these concerns, clindamycin appears relatively safe in minimal quantities and breastfeeding need not be discontinued 8, 5
Doxycycline - Limited Use Only
- Limit oral doxycycline use to 3 weeks maximum without repeating courses; use only if no suitable alternative is available 1
- Doxycycline has "unlikely" teratogenic potential but requires dosage adjustments and limited duration during lactation 5
Fluoroquinolones - Second-Line
- Ciprofloxacin and levofloxacin should not be first-line treatment, but if indicated, breastfeeding need not be interrupted as the risk of adverse effects is low 4, 5
Important Clinical Considerations
Monitoring the Infant
- All breastfed infants should be monitored for gastrointestinal effects including diarrhea, candidiasis, or altered intestinal flora 2, 3, 9
- Antibiotics in breast milk could potentially cause falsely negative cultures if the infant develops fever requiring evaluation 2, 3
Dosing Strategy
- Administer medication immediately following a breastfeed to minimize infant exposure, as peak milk concentrations typically occur 1-2 hours after oral medication 10
- Use the lowest effective dose for the shortest duration needed 2
- Choose drugs with short half-lives to minimize accumulation risk (e.g., cefotaxime 1.1 hours vs. ceftriaxone 7.25 hours) 10
Common Pitfalls to Avoid
- Do not unnecessarily discontinue breastfeeding when safe antibiotics are available 9, 4
- Avoid amoxicillin/clavulanic acid at high doses, as adverse effects increase with dosage (22.3% adverse effects vs. 7.5% with amoxicillin alone, though all were minor and self-limiting) 7
- Do not use chloramphenicol during breastfeeding, as it is not considered compatible 5