Omeprazole (OZ)

Omeprazole is a proton pump inhibitor used in the treatment of dyspepsia, peptic ulcer disease, gastroesophageal reflux disease, laryngopharyngeal reflux, and Zollinger–Ellison syndrome. Omeprazole is one of the most widely prescribed drugs internationally and is available over-the-counter in some countries. Omeprazole is a selective and irreversible proton pump inhibitor. It suppresses gastric acid secretion by specific inhibition of the hydrogen–potassium adenosinetriphosphatase (H +, K +-ATPase) enzyme system found at the secretory surface of parietal cells. It inhibits the final transport of hydrogen ions (via exchange with potassium ions) into the gastric lumen. Since the H +, K +-ATPase enzyme system is regarded as the acid (proton) pump of the gastric mucosa, omeprazole is known as a gastric acid pump inhibitor. Its inhibitory effect is dose-related. Omeprazole inhibits both basal and stimulated acid secretion irrespective of the stimulus.