Is profound acid inhibition safe?

Inhibitors of gastric acid secretion, particular proton pump inhibitors, ar e effective drugs in the treatment and prophylaxis of acid-related diseases . Proton pump inhibitors are therefore prescribed widely, often for minor c omplaints. Gastric acidity kills swallowed microorganisms, and acid secretion must be of biological importance because it is maintained in phylogenesis. Acid sec retion is controlled by feedback mechanisms, mainly via gastrin. A decrease in acidity always causes an increase in plasma gastrin. The trophic effect of gastrin leads to hyperplasia and neoplasia of the enterochromaffin-like (ECL) cell. ECL cell derived tumours in man were previously regarded as ra re, and also as rather benign. It is now clear that the ECL cell gives rise to a significant proportion of gastric carcinomas. Moreover, ECL cell carc inoids secondary to hypergastrinaemia may develop into highly malignant tum ours. Treatment with a proton pump inhibitor is followed by rebound acid hypersec retion and decreased efficiency of H-2-blockers, thus such treatment may in duce a type of physical dependence. It is therefore reasonable to be cautio us and not to treat younger (< 50 years) patients for long periods of time with profound inhibitors of gastric acid secretion. Chromogranin A in the b lood is a sensitive marker of the ECL cell mass, and it could be used to su rvey patients on long-term proton pump inhibitors.