The pharmacokinetics of ceftazidime were studied in 14 adult volunteers with different degrees of renal function. The elimination of ceftazidime was totally dependent on renal excretion. The clearance of ceftazidime ranged from 7.5 to 145.1 ml/min and correlated with both renal ceftazidime clearance and creatinine clearance (Cl(CR)). It is recommended that 0.5 to 2.0 g of ceftazidime be given in extended dosages, with intervals dependent on the renal function of the patient. Patients with a Cl(CR) of >50 ml/min should be given ceftazidime every 8 h, those with a Cl(CR) of 30 to 50 ml/min should be given the drug every 12 h, those with a Cl(CR) of 15 to 30 ml/min should be given the drug once a day, and individuals with a Cl(CR) of <15 ml/min should be given the drug on a 36- to 48-h regimen.