Hepatobiliary kinetics and excretion of ciprofloxacin.

The biliary excretion and metabolism of ciprofloxacin was studied in 25 hospitalized patients: 19 undergoing routine cholecystectomy and 6 with indwelling biliary drainage catheters. An intravenous dose of 200 mg of ciprofloxacin given 2.5 to 3.0 h prior to cholecystectomy resulted in concentrations in common duct bile, gallbladder bile, and gallbladder wall of 5.69 +/- 4.8, 5.43 +/- 3.34, and 2.52 +/- 1.30 micrograms/g, respectively, all at least fourfold greater than simultaneous concentrations in serum. Ciprofloxacin concentrations in common duct bile exceeded peak concentrations in serum in all but two patients with common duct obstruction. Multiple preoperative doses of ciprofloxacin prior to cholecystectomy increased concentrations in gallbladder bile by eightfold. Six patients with indwelling biliary drainage catheters also received 200 mg of ciprofloxacin intravenously. Less than 1% of the administered dose was excreted in bile as unchanged ciprofloxacin, and there was extensive metabolism. However, peak ciprofloxacin concentrations of 2.83 +/- 0.76 micrograms/ml in serum produced peak concentrations of 10.69 +/- 5.30 micrograms/ml in bile within 1.5 h after infusion and maintained concentrations of at least 0.5 microgram/ml in common duct bile for over 12 h in all patients. It appears that ciprofloxacin concentrations in bile will exceed the MICs for most susceptible biliary pathogens for a period of at least 12 h after a 200-mg intravenous dose.