Inhibition of pancreatic exocrine secretion and bile entry into the duodenum by isometheptene, a sympathomimetic agent.

We have studied the effect of isometheptene, an indirectly acting sympathomimetic with analgesic and antispastic properties, on secretin-cholecystokinin-stimulated pancreatic and biliary outputs. Isometheptene, infused intravenously at a dose of 100 mg in 30 min, significantly inhibited bicarbonate, enzyme, and bilirubin output in eight healthy subjects (compared to control values, the maximum percent inhibition was 34% for bicarbonate, 57% for lipase, 61% for chymotrypsin, and 86% for bilirubin). In four cholecystectomized subjects, the drug inhibited only pancreatic outputs. The inhibitory effect on pancreatic secretion, coupled with the analgesic action, suggest a potential benefit of this drug in acute pancreatic pathology.