Can you take cephalexin while breastfeeding?

What LactMed would consider instead

LactMed ends this record by naming the drugs it would consider in place of cephalexin. Whether any of them fits depends on what you are treating — this is the database’s list, not a recommendation from us.

• Cefazolin
• Floxacillin
• Oxacillin
• Methicillin
• Nafcillin
• Doxycycline
• Linezolid
• Minocycline
• Trimethoprim-Sulfamethoxazole
• Vancomycin

How much cephalexin gets into breastmilk

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).

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.

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. 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.

What has been seen in breastfed infants

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.

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.

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.

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.

Effects on milk supply

Relevant published information was not found as of the revision date.