Proton pump inhibitors (or "PPI"s) are a group of rugs whose main action is pronounced and long-lasting reduction of gastric acid production. They are the most potent inhibitors of acid secretion available today. The group followed and has largely superseded another group of pharmaceuticals with similar effects, but different mode-of-action, called H2-receptor antagonists. These drugs are among the most widely-selling drugs in the world as a result of their outstanding efficacy and safety. Structurally, the vast majority of these drugs are benzimidazole derivatives; however, promising new research indicates that imidazopyridine derivatives may be a more effective means of treatment.