Cephalexin Safety During Breastfeeding
Cephalexin is safe to use during breastfeeding and poses minimal risk to the nursing infant. 1, 2
Safety Profile
- Cephalexin, a first-generation cephalosporin, is considered safe for use during breastfeeding as β-lactam antibiotics generally have minimal adverse effects on nursing infants 1
- The FDA drug label confirms that while cephalexin is excreted in breast milk, it reaches a maximum level of only 4 mcg/mL and disappears from milk within 8 hours after administration 2
- Cephalexin has very low transfer into breast milk with relative infant doses of only 0.5% of the maternal dose, well below the notional 10% level of concern for infant exposure 3
Pharmacokinetics in Breastfeeding
- Cephalexin is rapidly absorbed in the upper intestine and quickly cleared by the kidneys, limiting prolonged exposure to the infant 4
- The drug does not accumulate in breast milk, with concentrations peaking at 4 hours post-dose and becoming undetectable by 8 hours 2
- Cephalexin has minimal protein binding and no measurable metabolism in the body, contributing to its favorable safety profile 4
Potential Concerns
- While systemic effects in the infant are unlikely due to low milk concentrations, local gastrointestinal effects such as diarrhea have been reported in some breastfed infants 3
- If diarrhea or other gastrointestinal disturbances occur in the infant, clinical reassessment may be warranted 3
- For mothers with significant renal impairment (creatinine clearance <30 mL/min), dose adjustment may be necessary as cephalexin is primarily excreted by the kidneys 4
Clinical Applications
- Cephalexin is particularly effective for treating skin and soft tissue infections, including mastitis in breastfeeding women 5, 6
- For treating mastitis in breastfeeding women, cephalexin is considered a first-line antibiotic option 5
- Continued breastfeeding during antibiotic treatment is recommended as it helps resolve mastitis and does not pose significant risks to the infant 5
Alternative Antibiotics
- If cephalexin is not tolerated or appropriate, amoxicillin/clavulanic acid is an alternative that is also considered safe during breastfeeding 5
- For penicillin-allergic patients, macrolides like erythromycin or azithromycin can be considered, though there is a very low risk of infantile hypertrophic pyloric stenosis if used in the first 13 days postpartum 5
Monitoring Recommendations
- If the infant develops diarrhea or other gastrointestinal symptoms while the mother is taking cephalexin, consider the possibility that the antibiotic may be contributing to these symptoms 3
- If symptoms worsen or do not improve within 48-72 hours of starting cephalexin, reevaluation is necessary to rule out complications or need for alternative antibiotics 5