Is Cefazolin safe while breastfeeding?
Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Cefazolin. This is a summary of that source — not our own verdict.
Effects on the breastfed infant
Relevant published information was not found as of the revision date.
Effects on milk supply
Relevant published information was not found as of the revision date.
Levels in milk
Maternal Levels. After a single 500 mg dose of cefazolin intramuscularly to 4 women, cefazolin was barely detectable in the mother's milk and not detected in their breastfed infants' serum.[ 1 ] After intramuscular doses of cefazolin 500 mg three times daily in 10 women, the peak concentration of cefazolin in milk was 0.9 mg/L.[ 2 ] Twenty women were given 2 grams of cefazolin intravenously over 10 minutes. Average milk levels were 1.25 mg/L at 2 hours, 1.51 mg/L at 3 hours and 1.16 mg/L at 4 hours after the dose.[ 3 ] After a single dose of 1 gram of cefazolin given intravenously to 15 women who were 1 month postpartum, milk cefazolin levels averaged 0.75 mg/L 2 hours after the dose.[ 4 ] Infant Levels. Relevant published information was not found as of the revision date.
Alternatives LactMed lists
“No published information” means the studies do not exist yet — not that Cefazolin is known to be harmful, and not that it is known to be safe. Your prescriber or pharmacist can weigh your baby's age and whether a better-studied alternative would do the same job. Worth asking before stopping a medicine you need.
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.