Ceftizoxime kinetics and renal handling.

The kinetics and renal handling of ceftizoxime were examined after intravenous and intramuscular injection and the effect of probenecid on its excretion was investigated. Peak serum level after 1000 mg IV was 60.5 microgram/ml and half-life (t 1/2) was 1.4 hr. Peak serum level (40.9 microgram/ml) was reached 1 hr after 1000 mg IM. When probenecid was added to the 1000-mg IM dose the peak level was 44.3 microgram/ml at 1 hr and serum levels at 2, 4, 6, and 8 hr were all higher than after ceftizoxime alone (P less than 0.01). The 1.85-hr t 1/2 of ceftizoxime alone was extended to 2.29 hr when probenecid was added. Ceftizoxime was shown to be actively secreted by the renal tubule; this secretion was decreased by probenecid.