Pharmacokinetic study of ceftazidime in bone and serum of patients undergoing hip and knee arthroplasty.
Twenty-eight patients undergoing hip arthroplasty and 15 undergoing knee arthroplasty, received chemoprophylaxis with ceftazidime 1.0 g administered intravenously at the time of induction of anaesthesia, followed by two doses of 500 mg given intramuscularly 6 and 12 h later. The mean bone concentration in hip arthroplasty showed a general rise towards a maximum of approximately 20 mg/kg when the exposure time (interval between antibiotic injection and removal of bone sample) was 35-40 min, with values ranging from 4.4 to 21.2 mg/kg (mean 14.4 mg/kg). The patients undergoing knee arthroplasty present a complicated pharmacokinetic problem, as the use of a tourniquet limits the exposure time. Bone concentrations of ceftazidime were highest at sampling times greater than 20 min in these patients (mean level of 15.9 mg/kg for femoral bone and 13.1 mg/kg for tibial bone).