NCIt definition : The sodium 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.;