[Effect of an antacid on duodenal pH in severe excretory pancreatic insufficiency].

pH was measured continuously in the lower duodenum before and 90 min after a standard meal in 15 controls and 13 patient with severe pancreatic insufficiency (PI); gastric acid secretion was unimpaired in all of them. 7 out of the 13 pat. with PI received additionally 30 ml of an A-Mg-silicate preparation (MegalacR) 45 min after the meal. Mean pH dropped after the meal from 6.9 to 6.2 in the controls and from 7.1 to 4.9 in the pat. with PI. The overall time of pH-values below 5 amounted to 0.5% of the measuring period in the controls, in PI-pat. to 35%. In pat. with PI there were additionally pH-values below 4 during 11% of the postcibal period. Antacid administration increased duodenal pH significantly but only over 15 min; this transient effect had, however, no significant influence on the overall time of the pH-values below 5 and 4. Al-Mg-silicate has obviously no relevant effect on the postcibal duodenal pH in pat. with PI and can therefore not be regarded as a means to prevent inactivation of pancreatic enzymes in the duodenum.