The influence of various secretory inhibitors on peptic activity.

The effects of pirenzepine and the H2-blocker ranitidine on pepsin secretion were studied in patients with duodenal ulcer. Pirenzepine and ranitidine in doses of 0.3 mg/kg-h inhibited pentagastrin-stimulated pepsin secretion by 63% and 82% respectively. The highest doses used of pirenzepine (0.6 mg/kg-h) and ranitidine (0.9 mg/kg-h) inhibited pepsin secretion by 69 and 93% respectively, whereas acid output was inhibited by 57 and 98%. Pirenzepine inhibited pepsin output more than hydrochloric acid output. However, pepsin output was less inhibited than hydrochloric acid output by ranitidine. These results suggest that pirenzepine might be especially useful in the treatment of those patients with peptic ulcer who have high proteolytic activity of their gastric juice.