Inhibition of food stimulated acid secretion by association of pirenzepine and ranitidine in duodenal ulcer patients.

The effects of pirenzepine and ranitidine alone and combined, on gastric acid secretion and gastrin release stimulated by liquid peptone meal were evaluated in 12 duodenal ulcer patients. Six patients received placebo and ranitidine 150 mg per os and the other six patients were given placebo, pirenzepine 50 mg and pirenzepine 50 mg plus ranitidine 150 mg per os, according to randomized sequences. In the first experiment ranitidine markedly inhibited (69%) gastric acid secretion for entire two hours period (p less than 0.01). In the second experiment acid secretion after pirenzepine, was reduced by 39% while the combination of pirenzepine plus ranitidine almost completely inhibited the meal stimulated acid secretion (99%). Mean integrated gastrin responses after pirenzepine and ranitidine alone as well as pirenzepine plus ranitidine were not significantly different from placebo. The results of these studies show that in duodenal ulcer patients, the simultaneous block of muscarinic and H2-receptors, suppresses meal stimulated gastric acid secretion, without affecting gastrin release. This therapeutic combination might be used in clinical situations (non-responders, Zollinger-Ellison syndrome) in which complete inhibition of gastric acid secretion is needed.