Is Cephalexin safe while breastfeeding?
Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Cephalexin. This is a summary of that source — not our own verdict.
Effects on the breastfed infant
In a prospective follow-up study, 7 nursing mothers reported taking cephalexin (dosage not specified). Two mothers reported diarrhea in their infants. No rashes or candidiasis were reported among the exposed infants.[ 6 ] A prospective, controlled study asked mothers who called an information service about adverse reactions experience by their breastfed infants. One of 11 cephalexin-exposed infants reportedly developed diarrhea during maternal cephalexin therapy.[ 7 ] A woman received intravenous cephalothin 1 g every 6 hours for 3 days. Her breastfed infant had a green liquid stool, severe diarrhea, discomfort and crying. The mother's drug regimen was then changed to oral cephalexin 500 mg plus oral probenecid 500 mg 4 times daily for another 16 days. The infant continued to have diarrhea during this time. The authors rated the diarrhea as probably related to cephalexin in milk.[ 5 ] A 4-month-old infant was treated with intravenous cefazolin for a urinary tract infection. Nine days after being discharged and cefazolin discontinuation, the infant developed a blistering rash over most of the body that was diagnosed as toxic epidermal necrolysis (TEN). The infant was being breastfed (extent unspecified) by his mother who had begun cephalexin 2 days prior to the onset of symptoms. A lymphocyte transformation test performed 4 weeks after treatment for TEN was completed found sensitization to both cefazolin and cephalexin. The infant's reaction was probably caused by cephalexin in breastmilk after initial sensitization and subsequent cross-reaction to cefazolin.[ 8 ]
Effects on milk supply
Relevant published information was not found as of the revision date.
Levels in milk
Maternal Levels. After a single 1 gram oral dose of cephalexin in 6 women who were 2 days postpartum, peak milk levels occurred 4 to 5 hours after the dose and averaged 0.51 mg/L (range 0.24 to 0.85 mg/L).[ 3 ] After a single 500 mg oral dose of cephalexin in 2 women (time postpartum not stated), peak milk levels of 0.7 mg/L occurred 4 hours after the dose.[ 4 ] A woman who was 28 days postpartum had been taking oral cephalexin 500 mg plus probenecid 500 mg 4 times daily for 16 days collected 12 fore-and hindmilk samples over a 16-hour period. Milk cephalexin levels ranged from about 0.4 to 1 mg/L over the milk collection period with little correlation to the times of the doses. The authors calculated that an exclusively breastfed infant would receive 112 mcg/kg daily which is much less than the recommended infant dosage of 25 to 100 mg/kg daily. The infant dosage in milk corresponds to about 0.5% of the maternal weight-adjusted dosage which is higher than in previous reports.[ 5 ] The higher milk levels in this patient may have been a result of the concurrent probenecid use. Infant Levels. Relevant published information was not found as of the revision date.
Alternatives LactMed lists
Source: NIH LactMed (National Library of Medicine).
Educational summary of an authoritative source — not medical advice. Never start, stop, or change a medicine while breastfeeding without confirming with your doctor.