Studies on absorption, distribution, metabolism and excretion of ceftazidime in Japan

Ceftazidime achieved mean serum levels of 54.6 and 119.7 mg/l at 5 min and 0.9 and 1.9 mg/l at 8 h after an intravenous bolus injection of 0.5 and 1 g in healthy male adult volunteers, showing a dose-related increase in serum levels. Serum half-lives were in the range from 1.6 to 1.7 h. About 90% of the given dose was excreted in the urine during the first 24 h. Following a 1-h intravenous drip infusion of 1 and 2 g, ceftazidime attained peak serum levels of 69.5 and 150.8 mg/l at the end of the infusion. Eighty-three and 90%, respectively, of the given doses were excreted in the urine during 24 h after the administration of 1 and 2 g of ceftazidime. When serum levels were compared after intravenous bolus injections of 1 g of ceftazidime and 1 g of cefoperazone in a crossover fashion, results were very similar for both compounds, but the 24-h urinary recovery rate was about three times higher with ceftazidime than with cefoperazone. An intravenous injection of 1 g ceftazidime resulted in peak biliary levels about 4 h after administration, longer than that of ceftizoxime compared in a crossover fashion, and subsequently fairly high levels were maintained for a longer time. Ceftazidime penetrated gall bladder tissues at concentrations sufficient to inhibit most of the pathogenic bacteria. In the urine collected from healthy volunteers 1 h after an intravenous injection of 1 g ceftazidime, no active metabolite was detected.