title: Pharmacokinetics of prophylactic cefazolin in parturients undergoing cesarean delivery.
abstract: The objectives of this work were (i) to characterize the pharmacokinetics of cefazolin in pregnant women undergoing elective cesarean delivery and in their neonates; (ii) to assess cefazolin transplacental transmission; (iii) to evaluate the dosing and timing of preoperative, prophylactic administration of cefazolin to pregnant women; and (iv) to investigate the impact of maternal dosing on therapeutic duration and exposure in newborns. Twenty women received 1 g of cefazolin preoperatively. Plasma concentrations of total cefazolin were analyzed from maternal blood samples taken before, during, and after delivery; umbilical cord blood samples obtained at delivery; and neonatal blood samples collected 24 h after birth. The distribution volume of cefazolin was 9.44 liters. [corrected] The values for pre- and postdelivery clearance were 7.18 and 4.12 liters/h, respectively. Computer simulations revealed that the probability of maintaining free cefazolin concentrations in plasma above 8 mg/liter during scheduled caesarean surgery was <50% in the cord blood when cefazolin was administered in doses of <2 g or when it was administered <1 h before delivery. Therapeutic concentrations of cefazolin persisted in neonates >5 h after birth. Cefazolin clearance increases during pregnancy, and larger doses are recommended for surgical prophylaxis in pregnant women to obtain the same antibacterial effect as in nonpregnant patients. Cefazolin has a longer half-life in neonates than in adults. Maternal administration of up to 2 g of cefazolin is effective and produces exposure within clinically approved limits in neonates.
authors.affiliation: Department of Anesthesia, Stanford University, Stanford, California, USA Department of Pharmaceutics and Industrial Pharmacy, Beni Suef University, Beni Suef, Egypt.
authors.forename: Mohammed H
authors.initials: MH
authors.lastname: Elkomy
authors.affiliation: Department of Anesthesia, Stanford University, Stanford, California, USA.
authors.forename: Pervez
authors.initials: P
authors.lastname: Sultan
authors.affiliation: Department of Anesthesia, Stanford University, Stanford, California, USA ddrover@stanford.edu.
authors.forename: David R
authors.initials: DR
authors.lastname: Drover
authors.affiliation: University of Colorado at Denver Health Science Center, Aurora, Colorado, USA.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Epshtein
authors.affiliation: University of Colorado at Denver Health Science Center, Aurora, Colorado, USA.
authors.forename: Jeffery L
authors.initials: JL
authors.lastname: Galinkin
authors.affiliation: Department of Anesthesia, Stanford University, Stanford, California, USA.
authors.forename: Brendan
authors.initials: B
authors.lastname: Carvalho
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D019072:Antibiotic Prophylaxis; D002437:Cefazolin / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D002585:Cesarean Section / Q000009:adverse effects; D005260:Female; D006207:Half-Life; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D011300:Preoperative Care; D013530:Surgical Wound Infection / Q000517:prevention & control*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D002437:Cefazolin
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