From the FDA Drug Label
The excretion of cephalexin in human milk increased up to 4 hours after a 500 mg dose; the drug reached a maximum level of 4 mcg/mL, then decreased gradually, and had disappeared 8 hours after administration. Caution should be exercised when cephalexin is administered to a nursing woman
- Cephalexin is excreted in human milk, with a maximum level of 4 mcg/mL reached 4 hours after a 500 mg dose.
- The drug disappears from milk 8 hours after administration.
- Caution is recommended when cephalexin is administered to a nursing woman 1 1.
- Based on this information, cephalexin can be used during breastfeeding, but with caution.
From the Research
Keflex (cephalexin) is generally considered safe during breastfeeding, as it is compatible with nursing and minimal amounts pass into breast milk, posing a low risk to the breastfed infant. According to the most recent study from 2022 2, when prescribing medications for a breastfeeding patient, those with the lowest risk to the infant should be selected. Cephalexin is a cephalosporin antibiotic, and as stated in the 2003 study 3, cephalosporins are considered appropriate for use in lactating women at dosages at the low end of the recommended dosage range.
The benefits of treating maternal infection with cephalexin typically outweigh the minimal risks to the breastfed infant. If the infant develops diarrhea, thrush, or diaper rash while the mother is taking Keflex, it is essential to contact the healthcare provider, as these could potentially be related to changes in the infant's gut flora from exposure to the antibiotic through breast milk. However, these side effects are uncommon.
It is crucial to inform the healthcare provider that you are breastfeeding before starting any medication, including Keflex, to ensure it's appropriate for your specific situation. The American Academy of Pediatrics classifies cephalexin as compatible with breastfeeding, supporting its safe use during lactation. If concerns about taking Keflex while breastfeeding arise, discussing them with the healthcare provider is recommended to make an informed decision.