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Cefazolin Pregnancy and Breastfeeding Warnings

Cefazolin is also known as: Ancef, Kefzol

Cefazolin 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

See references

Cefazolin 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.

See references

References for pregnancy information

  1. "Product Information. Ancef (cefazolin)." SmithKline Beecham, Philadelphia, PA.
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  3. Cerner Multum, Inc. "Australian Product Information." O 0
  4. Czeizel AE, Rockenbauer M, Sorensen HT, Olsen J "Use of cephalosporins during pregnancy and in the presence of congenital abnormalities: A population-based, case-control study." Am J Obstet Gynecol 184 (2001): 1289-96
  5. "Product Information. Kefzol (cefazolin)." Lilly, Eli and Company, Indianapolis, IN.
  6. Melbourne: Therapeutic Guidelines Limited "eTG complete [Online] Available from: URL:" ([2014, Nov -]):
  7. Heikkila A, Erkkola R "Review of beta-lactam antibiotics in pregnancy - the need for adjustment of dosage schedules." Clin Pharmacokinet 27 (1994): 49-62
  8. Fiore Mitchell T, Pearlman MD, Chapman RL, Bhatt-Mehta V, Faix RG "Maternal and transplacental pharmacokinetics of cefazolin." Obstet Gynecol 98 (2001): 1075-9
  9. TGA. Therapeutic Goods Administration. Australian Drug Evaluation Committee "Prescribing medicines in pregnancy: an Australian categorisation of risk of drug use in pregancy. Available from: URL:" ([1999]):

References for breastfeeding information

  1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  2. Cerner Multum, Inc. "Australian Product Information." O 0
  3. Briggs GG, Freeman RK, Yaffe SJ.. "Drugs in Pregnancy and Lactation. 5th ed." Baltimore, MD: Williams & Wilkins (1998):
  4. "Product Information. Kefzol (cefazolin)." Lilly, Eli and Company, Indianapolis, IN.
  5. "American Academy of Pediatrics. Committee on Drugs. The transfer of drugs and other chemicals into human milk." Pediatrics 108 (2001): 776-89
  6. United States National Library of Medicine "Toxnet. Toxicology Data Network. Available from: URL:" ([cited 2013 -]):
  7. Melbourne: Therapeutic Guidelines Limited "eTG complete [Online] Available from: URL:" ([2014, Nov -]):
  8. Yoshioka H, Cho K, Takimoto M, et al "Transfer of cefazolin into human milk." J Pediatr 94 (1979): 151-2
  9. "Product Information. Ancef (cefazolin)." SmithKline Beecham, Philadelphia, PA.

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