The antisecretory effects of RP 40 749 in patients with previous duodenal ulcer.

Thirteen male patients with a history of duodenal ulcer were given 150 mg RP 40 749 or placebo tablets at bedtime in a double-blind crossover study. The medication was given for two periods of 10 days with an 11-day wash-out period between. pH and pepsin concentrations were determined each hour in aspirates of gastric juice for 24 h on day 1, 10, 22, 31, and a 2-h collection of gastric juice was examined in the middle of the treatment and wash-out periods. At defined hours blood samples were examined for gastrin, somatostatin, and pancreatic polypeptide (PP) by radioimmunological methods, and concentrations of RP 40 749 were determined in blood and gastric juice. Meals were served at fixed hours on days 1, 10, 22, and 31. After treatment with RP 40 749 a highly significant elevation of pH was found after the 1st day compared with placebo, most pronounced during night hours. The pepsin activity was slightly elevated. The serum concentrations of gastrin were increased and those of somatostatin and PP decreased during the first 3-4 h after medication, with a subsequent normalization. No side effects were observed.