NCIt definition : The magnesium salt form of a benzimidazole with selective and irreversible proton
pump inhibitor activity. In the acidic compartment of parietal cells, omeprazole is
protonated and converted into the active achiral sulfenamide; the active sulfenamide
forms one or more covalent disulfide bonds with the proton pump hydrogen-potassium
adenosine triphosphatase (H /K ATPase), thereby inhibiting its activity and the parietal
cell secretion of H ions into the gastric lumen, the final step in gastric acid production.
H /K ATPase is an integral membrane protein of the gastric parietal cell.;