Is amoxicillin (amoxicillin) safe to use during lactation in a breastfeeding woman?

Amoxicillin Safety During Lactation

Amoxicillin is explicitly classified as "compatible" with breastfeeding by the European Respiratory Society/Thoracic Society of Australia and New Zealand (ERS/TSANZ) guidelines and the American Academy of Dermatology, representing the highest level of safety designation for antibiotics during lactation. 1

Safety Classification and Evidence Base

• Amoxicillin is classified as FDA Pregnancy Category B, and the FDA drug label confirms that penicillins are excreted in human milk, though the amounts are low. 2
• Multiple international guidelines, including the European Respiratory Society, explicitly list amoxicillin as "compatible" with breastfeeding—the most favorable safety classification available. 1
• Research confirms that penicillins and aminopenicillins, including amoxicillin, are present in breast milk at low concentrations. 1, 3

Clinical Recommendations

• Breastfeeding should not be interrupted when amoxicillin is prescribed, as the benefits of continued breastfeeding outweigh the minimal risks of amoxicillin exposure through breast milk. 1
• The American Academy of Dermatology recommends amoxicillin as a safe and effective choice during breastfeeding. 1
• Standard adult dosing of amoxicillin (250 mg twice daily up to 500 mg three times daily) can be used without modification in breastfeeding mothers. 1

Infant Monitoring Considerations

• All breastfed infants whose mothers are taking antibiotics, including amoxicillin, should be monitored for gastrointestinal effects (mild diarrhea or gastroenteritis), though serious adverse events are rare. 1
• Antibiotics in breast milk may alter intestinal flora in the infant, potentially causing mild GI symptoms. 1
• Antibiotics in breast milk could potentially cause falsely negative cultures if the breastfed infant develops fever requiring evaluation. 1

Important Caveat: Amoxicillin/Clavulanic Acid (Augmentin)

• While amoxicillin alone is fully compatible with breastfeeding, amoxicillin/clavulanic acid (Augmentin) requires additional consideration. 1
• The European Respiratory Society guidelines recommend caution when using amoxicillin/clavulanic acid in women at risk of pre-term delivery due to a very low risk of necrotizing enterocolitis, but this caveat applies to pregnancy/delivery contexts, not to postpartum breastfeeding in term infants. 1
• For breastfeeding after term delivery, amoxicillin/clavulanic acid remains fully compatible and safe, though research shows a higher rate of minor infant adverse effects (22.3%) compared to amoxicillin alone (7.5%), primarily dose-dependent GI symptoms that are self-limiting and do not necessitate interruption of breastfeeding. 4

Practical Clinical Algorithm

• First-line choice: Prescribe amoxicillin at standard doses without hesitation in breastfeeding mothers requiring a penicillin antibiotic. 1
• No need to pump and discard: Continue normal breastfeeding throughout the treatment course. 1
• Monitor infant for: Mild diarrhea, fussiness, or diaper rash (signs of altered gut flora). 1
• Reassure mother: The small amounts transferred through breast milk are not therapeutic for the infant and pose minimal risk. 1