Is amoxicillin (amoxicillin/clavulanate) safe to use in a breastfeeding mother?

Amoxicillin/Clavulanic Acid Safety During Breastfeeding

Amoxicillin/clavulanic acid is safe to use in breastfeeding mothers and is specifically recommended for breastfeeding patients who require systemic antibiotics. 1

Safety Profile in Breastfeeding

• Amoxicillin/clavulanic acid is classified as compatible with breastfeeding according to both FDA (Category B) and clinical practice guidelines 1
• The 2025 North American Clinical Practice Guidelines specifically suggest using oral amoxicillin/clavulanic acid in breastfeeding patients who require systemic antibiotics 1
• While amoxicillin-class antibiotics are excreted in human milk, the amount transferred is minimal and generally considered safe for the infant 2

Considerations When Prescribing

• Some infants may experience mild adverse effects when exposed to amoxicillin/clavulanic acid through breast milk:

  • In a comparative study, 22.3% of breastfed infants whose mothers took amoxicillin/clavulanic acid experienced mild, self-limiting adverse effects, compared to 7.5% in the amoxicillin-only group 3
  • The rate of adverse effects increased with higher maternal dosages 3
  • All reported adverse effects were minor and self-limiting, not requiring interruption of breastfeeding 3

• To minimize potential effects on the infant:

  • Consider timing medication administration immediately after breastfeeding to minimize peak concentration exposure to the infant 4
  • Monitor the infant for any unusual symptoms such as diarrhea or changes in feeding patterns 4, 5

Clinical Context

• When antibiotics are required for a breastfeeding mother, the benefits of treating the maternal infection typically outweigh the minimal risks to the infant 5, 6
• Amoxicillin/clavulanic acid is preferred over certain other antibiotics during breastfeeding:
  • Preferred over doxycycline, which should be limited to 3 weeks without repeating courses if no suitable alternative is available 1
  • Preferred over clindamycin, which may increase risk of GI side effects in the infant 1

Important Caveats

• Most systemic antibiotics will be present in breast milk to some degree, which could potentially:
  • Cause falsely negative cultures if the breastfed infant develops a fever requiring evaluation 1
  • Produce mild gastrointestinal effects due to alteration of intestinal flora 1
• The necessity of prescribing antibiotics should always be carefully assessed, weighing the benefits for the mother against any potential risks to the infant 4, 7