[Biliary diffusion of tazocillin in man].

The objective of this study was to determine the extent of biliary excretion of tazocillin, a combination of piperacillin and tazobactam administered as an intravenous infusion in a dose of 4 g of piperacillin and 0.5 g of tazobactam. In 10 patients, piperacillin and tazobactam levels were determined in serum, main bile duct bile, gallbladder bile, and gallbladder wall specimens harvested during a cholecystectomy procedure 1 h after completion of a tazocillin infusion. In five other patients, piperacillin and tazobactam levels were determined in bile collected from a main bile duct T-tube during 12 h following a tazocillin infusion given seven days after cholecystectomy. HPLC was used to assay both compounds. Piperacillin and tazobactam levels in the intraoperative specimens were as follows: 69.1 +/- 13.8 and 9.9 +/- 1.7 micrograms/ml, respectively, in the serum; 630 +/- 133 and 11.9 +/- 2.2 micrograms/ml, respectively, in the main bile duct bile; 342 +/- 114 and 7.7 +/- 2.3 micrograms/ml, respectively, in the gallbladder bile; and 49.3 +/- 20.2 and 2.9 +/- 0.6 micrograms/g, respectively, in the gallbladder wall. In the T-tube bile specimens, peak piperacillin and tazobactam levels were 358 +/- 281 and 9.9 +/- 3.3 micrograms/ml, respectively, after 1 h; total biliary excretion over 12 hours was 28.3 +/- 18.0 mg and 1.0 +/- 0.5 mg, i.e., 0.7 +/- 0.4% and 0.2 +/- 0.1% of the dose, respectively. The levels of piperacillin and tazobactam found in bile and gallbladder wall specimens in this study suggest that tazocillin may prove valuable for the prevention and treatment of biliary infections.