Cefazillin Use In Pregnancy & Lactation

Pregnancy: Cefazolin is in US Pregnancy Category B which means animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women or animal studies have shown an adverse effect but adequate and well-controlled studies in pregnant women have failed to demonstrate a risk to the fetus in any trimester.
Adverse effects were not observed in animal reproduction studies. Adverse events have not been reported in the fetus following administration of cefazolin prior to cesarean section. Cefazolin crosses the placenta. Drug levels in cord blood after administration of cefazolin are approximately one-fourth to one-third maternal drug levels.
Cefazolin is recommended for group B streptococcus prophylaxis in pregnant patients with a nonanaphylactic penicillin allergy. It is also one of the antibiotics recommended for prophylactic use prior to cesarean delivery in women at high risk for endocarditis.
In addition, the pharmacokinetics of cefazolin are altered in pregnant women. The half-life is shorter, the AUC is smaller, and the clearance and volume of distribution are increased.
Labor and Delivery: No information.
Lactation: Small amounts of cefazolin are excreted in breast milk. Caution should be exercised when administering cefazolin to nursing women. Non dose-related effects could include modification of bowel flora.