Amikacin sulfate levels in human serum and bile

Amikacin levels in blood and bile were measured in 10 patients who underwent cholecystectomy and T-tube drainage. Each patient received 500 mg of amikacin intravenously 12 h preoperatively, during surgery, and every 12 h thereafter for four more doses. Average levels of amikacin in bile were 8.3 micrograms/ml at 1 h after the intraoperative dose, with a bile/serum ratio of 0.44. Postoperative doses at 1 h produced levels in bile of 3.8 to 4.2 micrograms/ml, with a bile/serum ratio of 0.15 to 0.22. Levels in bile decreased at a rate lower than levels in blood, and bile/serum ratios increased from 0.54 at 2 h to 0.93 at 12 h. Amikacin accumulated in bile at 6 h after the intravenous dose.