Anti-ulcer drugs: Current developments and future predictions

Histamine H₂ receptor antagonists have been the number one best-selling drugs in the world for more than a decade. However, the dominance of this particular class of gastric anti-secretory agent in the therapy of peptic ulcer and associated diseases is being challenged by proton pump inhibitors. The latter drugs are more effective inhibitors of acid secretion by virtue of their ability to specifically block the parietal cell H/K-ATPase enzyme responsible for formation of HCl. Indeed, by analogy with anti-hypertensive therapy, enzyme inhibitors could eventually displace receptor antagonists as the mast valuable product segment in the anti-ulcer market. Whether a third major cycle of innovative anti-ulcer drugs will supersede H₂ receptor antagonists and proton pump inhibitors is more difficult to predict given the efficacy of current agents, the requirement for pharmaceutical companies to focus drug development in areas of clinical need such as inflammatory bowel disease and colon cancer, and a decline in the incidence of ulcer disease itself. A drug to eradicate Helicobacter pylori represents the most attractive option for developing the next generation of anti-ulcer agents. A major initiative to discover a novel drug would be justified if evidence implicating H.pylori infection as a cause of cancer of the stomach was substantiated and such therapy was demonstrated to prevent both peptic ulcer and gastric cancer.