Abnormal responses to morphine-neostigmine in patients with undefined biliary type pain

The occurrence of pain and changes in serum concentrations of liver enzymes and amylase were investigated after challenge with intramuscular morphine (0.12 mg/kg) and neostigmine (0.012 mg/kg) in 25 control subjects and 80 patients with undefined biliary type pain, both with and without prior cholecystectomy. Peak enzyme concentrations were reached at four hours after the injection of morphine-neostigmine. When compared with controls, patients who had pain after cholecystectomy and a dilated bile duct and/or spontaneous changes in liver enzymes, had a higher frequency of drug induced pain and a higher frequency of rise (greater than 2 X N) in serum concentrations of aspartate aminotransferase (AST) and amylase; postcholecystectomy patients with pain but without bile duct dilatation, and patients with pain without prior cholecystectomy, had a higher frequency of drug induced pain but did not have a higher frequency of enzyme rise. Increases in liver enzymes after morphine-neostigmine were abolished by endoscopic sphincterotomy. Thirty three patients with a dilated bile duct and/or spontaneous changes in liver enzymes were also studied by endoscopic manometry of the sphincter of Oddi: similar frequencies of enzyme changes were observed in patients with normal manometry as in those with various manometric disorders. Increases in serum concentrations of liver enzymes after morphine-neostigmine may be explained by high biliary pressures resulting from an exaggerated motor response in the sphincter of Oddi.