Proton pump inhibitors is a group of drugs whose main action is pronounced and long-lasting reduction of gastric acid production. The group followed another group of pharmaceuticals with similar action called H₂ antagonists. Proton pump inhibitors act by blocking the hydrogen-potassium adenosine triphosphatase enzyme system (the so called proton pump ) of the gastric parietal cell. Hence the enzyme inhibited is the terminal stage in gastric acid production. These drugs are utilized in the treatment of many conditions such as:

• duodenal and gastric ulcers
• Zollinger-Ellison syndrome
• Erosive reflux oesophagitis.