Cytoprotective Drugs

Summary

Cytoprotection is defined as the ability of a pharmacological agent to reduce or prevent gastric mucosal necrosis produced by a variety of ulcerogenic and necrotising agents. The key feature of cytoprotection is that mucosal protection is accomplished without inhibition of gastric acid secretion. Since the first demonstration of cytoprotection by prostaglandins, other agents such as essential fatty acids, sucralfate, liquorice, sulfhydryl compounds and aluminium-containing antacids have been shown to possess cytoprotective properties. In recent studies, the efficacy of the antacids aluminium hydroxide and ‘Maalox-70’ in protecting rat gastric mucosa against alcohol-induced necrosis was compared with that of the H₂-receptor antagonists, cimetidine, ranitidine, famotidine and nizatidine. The data demonstrated that both antacids effectively protected the gastric mucosa against alcohol-induced gross lesions and deep histological necrosis. Acidified with hydrochloric acid, ‘Maalox-70’ gave 8-fold better protection than a regular non-acidified ‘Maalox-70’. This clearly indicates that antacid-afforded mucosal protection is entirely independent of the ability of antacids to neutralise luminal acid and, therefore, has all the features of cytoprotection. In contrast, the H₂-receptor antagonists are completely ineffective in protecting the gastric mucosa against alcohol injury.