Abstract
The pharmacokinetics of ceftizoxime (CZX), a new semisynthetic cephalosporin antibiotic, were examined in 8 normal subjects and 25 patients with different endogeneous creatinine clearances (Ccr) on the basis of a one-compartment open model. Each subject was injected a single 500 mg dose of ceftizoxime intramuscularly, and serum and urinary concentrations were measured by a bioassay. The mean peak concentration of ceftizoxime in serum was achieved 30 minutes after administration in normal subjects. The mean serum halflife of ceftizoxime was calculated for 1.45 hours in normal subjects, and increased in patients along with increasing impairment of renal function. A significant linear correlation between the elimination rate constant and Ccr was demonstrated (p<0.001). In normal subjects, 77. 6% of the administered dose was excreted in the urine within the first 6 hours. The urinary excretion rate declined gradually in patients as a degree of renal impairment advanced.
