Advancing age and acute infection influence the kinetics of ceftazidime

The pharmacokinetics of ceftazidime were studied after single intravenous injections of 2 g in 10 healthy, elderly male volunteers (63-76 years old). None of the subjects were on concurrent drug treatment and all had normal age-correlated glomerular filtration rate. Mean values for major pharmacokinetic variables were: terminal half-life 2.63 h, area under the serum concentration curve 417.6 h mg/l, total clearance 74.6 ml/(min 1.73 m2), renal clearance 53.6 ml/(min 1.73 m2), urinary recovery/12 h 71.7% of dose and apparent volume of distribution (Vss) 15.0 l/1.73 m2. Data were compared with our earlier findings in studies of young male volunteers and elderly, acutely ill male patients. Advanced age was accompanied by a reduction in clearance of ceftazidime, while no significant age-related changes in distribution were noted. Acute infection was associated with increased Vss and enhanced renal clearance; alterations possibly caused by fever-induced changes in vascular permeability and renal blood-flow.