Pharmacokinetics of ceftazidime in patients with biliary tract disease

After administration of ceftazidime as a 1 g i.v. bolus injection, its concentration was measured by HPLC at frequent intervals in serum, bile and tissue from different parts of the biliary tract in 32 patients undergoing operation for biliary tract disease. In bile from the functioning gallbladder and common bile duct, a high concentration of ceftazidime was found, mean 18.5 and 26.6 mg/l, respectively. In bile from the non-functioning gallbladder, a very low concentration was found (less than 1.5 mg/l). Ceftazidime in the gallbladder wall varied considerably with the type and degree of inflammation judged histologically; the mean level was 21.3 mg/kg. The elimination half-life of ceftazidime was 1.74 h, apparent volume of distribution 20.01 and total plasma clearance 133 ml/min. In bile from T-tube specimens a high concentration was found, the mean peak values being 27.2 mg/l. However, biliary excretion of the drug was low at less than 0.5% of the administered dose. These concentrations of ceftazidime were sufficient to inhibit the in-vitro growth of pathogens, namely the Enterobacteriaecae commonly responsible for biliary tract infection.