The influence of cimetidine on the acid gastro-oesophageal reflux in duodenal ulcer patients.

Using a method described earlier, an investigation of the gastro-oesophageal region was made on duodenal ulcer patients before and during cimetidine treatment. During cimetidine treatment there was a small increase in the gastro-oesophageal sphincter pressure (p less than 0.05), although the pressure still was lower than in normal individuals (p less than 0.05). The acid perfusion test and the acid-clearing test were unchanged. The intensity of the acid gastro-oesophageal reflux at pH less than or equal to 4 was reduced p less than 0.05) but still greater than in normal individuals (p less than 0.05). A tendency to an increase of the intragastric pH postprandially (0.05 less than p less than 0.01) was found during treatment, whereas the intragastric pH fasting 12 h after the intake of the last tablet was unchanged. There was no change in the number of amplitudes registered at the proximal and distal pressure catheters (p greater than 0.1), whereas the reversed peristaltic activity still was increased compared with normal individuals (p less than 0.00u). Before treatment a reflux episode at pH less than or equal to 3 needed longer time and greater peristaltic activity to be cleared than was the case during treatment. Nineteen of 20 patients improved their symptoms during treatment. Cimetidine increased the gastro-oesophageal sphincter pressure in duodenal ulcer patients, which may be due to either the reduced intragastric acid secretion or to a direct influence on the gastro-oesophageal region. The reduction in the acid gastro-oesophageal reflux is partly due to an increased gastro-oesophageal sphincter pressure and partly due to a reduced output of acid reflux material. Low pH and the volume of the reflux material in the distal part of the oesophagus are important in regulating the peristaltic activity in duodenal ulcer patients.