Ampicillin concentrations in pancreatic fluid bile obtained at endoscopic retrograde cholangiopancreatography (ERCP).

To investigate the distribution of ampicillin to the pancreas, ampicillin concentrations in pancreatic fluid obtained at endoscopic retrograde cholangiopancreatography (ERCP) were determined. Alternatively, ampicillin concentrations in bile obtained via ERCP were determined. Ten subjects with non-acute biliary-tract or pancreatic disease received a single dose of ampicillin (250 or 500 mg) parentally before ERCP. Timed simultaneous specimens of blood and pancreatic fluid or bile were obtained. Serum concentrations of ampicillin were measured in all subjects. In six of seven subjects no ampicillin was detectable in pancreatic fluid; in the seventh less than 1 microgram/ml was found. Pancreatic duct anatomy did not appear to correlate with pancreatic fluid concentrations. Failure to detect ampicillin in pancreatic fluid may account for results of clinical studies in which no clinical benefit from ampicillin has been found. Low or undetectable concentrations of ampicillin were found in bile; these concentrations in bile obtained at ERCP are similar to those found previously in bile recovered at biliary-tract surgery.