title: Assessment of cefazolin and cefuroxime tissue penetration by using a continuous intravenous infusion.
abstract: A continuous intravenous infusion was used to assess the tissue penetration of cefazolin (14 subjects) and cefuroxime (15 subjects) in orthopedic surgery patients. Subjects were randomly assigned to receive a continuous intravenous infusion of cefazolin (mean, 178.6 mg/h) or cefuroxime (mean, 330.0 mg/h) at a rate estimated to achieve a target steady-state total concentration of 50 micrograms/ml in serum. The infusion was initiated 12 to 14 h before surgery, and blood and muscle tissue samples were collected intraoperatively at the times of incision and wound closure. Although there was a significant difference between the free concentrations of cefazolin (at incision, 9.3 micrograms/ml; at closure, 9.2 micrograms/ml) and cefuroxime in serum (at incision, 26.9 micrograms/ml; at closure, 31.8 micrograms/ml), there was no difference in the total concentrations in muscle at either surgical incision (cefazolin, 6.1 micrograms/g; cefuroxime, 5.6 micrograms/g) or wound closure (cefazolin, 7.7 micrograms/g; cefuroxime, 7.4 micrograms/g). There was a significant correlation between the pooled free serum and total muscle concentrations for cefazolin (P = 0.001); however, there was no correlation between these variables with the pooled cefuroxime data (P = 0.403). These findings indicate that the free drug concentration in serum alone is not consistently predictive of the total concentration of cephalosporin in muscle.
authors.affiliation: University of Georgia College of Pharmacy, Augusta.
authors.forename: J E
authors.initials: JE
authors.lastname: Connors
authors.forename: J T
authors.initials: JT
authors.lastname: DiPiro
authors.forename: R G
authors.initials: RG
authors.lastname: Hayter
authors.forename: K D
authors.initials: KD
authors.lastname: Hooker
authors.forename: J A
authors.initials: JA
authors.lastname: Stanfield
authors.forename: T R
authors.initials: TR
authors.lastname: Young
mesh_terms: D002437:Cefazolin / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D002444:Cefuroxime / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D002511:Cephalosporins / Q000493:pharmacokinetics*; D006801:Humans; D007262:Infusions, Intravenous; D009132:Muscles / Q000378:metabolism*; D011897:Random Allocation
chemical_list: D002511:Cephalosporins; D002437:Cefazolin; D002444:Cefuroxime