Gentamicin levels in the human biliary tract

The concentration of gentamicin in bile was determined in sixteen patients who underwent surgery of the biliary tract. Peak levels of bile were obtained 2-3 hr after a single im injection of 1 mg of gentamicin per kg. Prolonged studies in three patients indicated that gentamicin was still present in bile 8 hr after the injection. Ten patients without obstruction of the cystic duct had a mean gentamicin level of 2.0 μg/ml in bile. This level was 37% of the mean level in serum. Six patients with cystic.-duct obstruction had no detectable gentamicin in gallbladder bile, despite the presence of gentamicin in common-duct bile in three of these patients. Minimal abnormalities were present in tests of liver function in 14 of the 16 patients stüdied but did not correlate with the levels of gentamicin achieved in the bile.