Biliary pharmacokinetics of sulbactam plus ampicillin in humans

The biliary pharmacokinetics of sulbactam and ampicillin was investigated in 19 patients with normal liver function who were undergoing surgery of the biliary tract. The combination of sulbactam (0.5 g) plus ampicillin (1 g) was given intravenously to five patients with T-tube drainage of the common bile duct. Mean peak concentrations of sulbactam (19.4 micrograms/ml) and ampicillin (471 micrograms/ml) in the bile occurred 0.5-1 hr after administration. Biliary excretion was estimated to account for approximately 0.24% of the sulbactam dose and 2.8% of the ampicillin dose. Fourteen other patients received the same dose of sulbactam/ampicillin immediately before elective cholecystectomy. Respective mean concentrations of sulbactam and ampicillin at the time of gallbladder removal were 4.3 micrograms/ml and 15.9 micrograms/ml in gallbladder bile and 6.3 micrograms/g and 7.7 micrograms/g in gallbladder wall tissue. These results, together with the antibacterial spectrum and potency of the combination, suggest that sulbactam/ampicillin is suitable for prophylactic use in biliary tract surgery.