Single nocturnal doses of pirenzepine effectively inhibit overnight gastric secretion.

The gastric antisecretory effects of two dose levels of pirenzepine given at night were investigated in a group of healthy male volunteers. Compared with placebo, three days of treatment with pirenzepine 100 mg nocte or 150 mg nocte inhibited mean nocturnal intragastric acidity by 54% and 53%, respectively (p less than 0.01). The volume of gastric juice secreted was reduced by 47% and 52% (p less than 0.005), by 100 mg and 150 mg nocte, respectively. Each dose suppressed mean gastric acid output by 67% (p less than 0.001). Pepsin output was not significantly altered. There were no differences in effect between the two dose levels studied, but side-effects such as dry mouth were only seen with the higher dose. Pirenzepine 100 mg is the optimum dose which can conveniently be given at night. This will limit side-effects, and may be a useful treatment for patients with duodenal ulcer.