[Proton pump inhibitors: their merits and demerits, and perspectives for future investigation]

Proton pump inhibitors have a potent antisecretory activity and are under development in many pharmaceutical companies. In this paper, the merits and demerits of the drugs, which have been revealed by experimental studies in humans and animals, are reviewed. Issues of the drugs which remain to be examined in the future are also discussed in reletion to their application in peptic ulcer patients. The issues include 1) genotoxicity of the drugs with long-term treatment; 2) their possible contribution to defensive factors of gastro-intestinal mucosa; 3) their antimicrobial activity against Helicobacter pylori; 4) interaction with the other drugs; etc.