A 2,2,2-trifluoroethoxypyridyl derivative of timoprazole that is used in the therapy of STOMACH ULCERS and ZOLLINGER-ELLISON SYNDROME. The drug inhibits H(+)-K(+)-EXCHANGING ATPASE which is found in GASTRIC PARIETAL CELLS. Lansoprazole is a racemic mixture of (R)- and (S)-isomers.

A substituted benzimidazole prodrug with selective and irreversible proton pump inhibitor activity. Lansoprazole prodrug is converted to an active sulfonamide derivative in the acidic environment of the gastric parietal cell; the sulfonamide derivative binds to the gastric proton pump H+/K+ ATPase and forms a stable disulfide bond with the sulfhydryl group near the potassium-binding site on the luminal side, resulting in inactivation of the ATPase and a reduction in gastric acid secretion. This agent does not have anticholinergic or histamine H2 -receptor antagonistic properties.