Cefazolin (injection) Pregnancy Warnings
Animal studies have failed to reveal evidence of fetal harm or impaired fertility. This drug crosses the placental barrier into cord blood and amniotic fluid. There are no controlled data in human pregnancy. No adverse fetal effects have been reported.
A positive direct and indirect antiglobulin (Coombs) test may occur in neonates of mothers who received cephalosporins before delivery.
When this drug was administered before caesarean section, drug levels in cord blood were one-fourth to one-third of maternal drug levels. No adverse fetal effects have been reported.
AU TGA pregnancy category B1: Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed. Studies in animals have not shown evidence of an increased occurrence of fetal damage.
US FDA pregnancy category B: Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women.
This drug should be used during pregnancy only if clearly needed and the benefit outweighs the risk; safety has not been established during pregnancy.
AU TGA pregnancy category: B1
US FDA pregnancy category: B
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Cefazolin (injection) Breastfeeding Warnings
According to limited data, maternal doses up to 2 g produce low levels in breast milk.
After a single 500 mg IM dose in 4 nursing women, this drug was barely detectable in the breast milk and not detected in the serum of their breastfed infants.
After 500 mg IM 3 times a day in 10 women, the peak drug level in milk was 0.9 mg/L.
After 2 g IV (infused over 10 minutes) in 20 women, milk levels averaged 1.25 mg/L at 2 hours, 1.51 mg/L at 3 hours, and 1.16 mg/L at 4 hours after dosing.
After a single 1 g IV dose in 15 women (1 month postpartum), milk drug levels averaged 0.75 mg/L at 2 hours after dosing.
Use is considered acceptable; caution is recommended. Benefit to mother should outweigh risk to the infant.
Excreted into human milk: Yes (in small amounts)
Comments:
-Low levels in milk are not expected to cause harmful effects in the nursing infant.
-Disruption of infant's gastrointestinal flora (resulting in diarrhea or thrush) reported occasionally with cephalosporins, but such effects have not been adequately evaluated; possibility of sensitization should be considered.
-This drug is considered compatible with breastfeeding by the American Academy of Pediatrics and other experts.
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