[Acid secretion inhibition with new mechanisms of action: substituted benzimidazole]

Omeprazole and other substituted benzimidazoles produce a marked inhibition of gastric acid secretion with a long duration of action. Any kind of stimulated acid secretion is inhibited by the substituted benzimidazoles. The inhibitory mechanism of action is very selective. The substituted benzimidazoles inhibit the parietal cell H+, K+-ATPase, an enzyme which is the proton pump in the secretory membrane of the parietal cell. An oral daily dose of 15 mg omeprazole in humans produced about 80% acid inhibition just after dosage and about 40% 24 hours later. Preliminary results in duodenal ulcer patients show that a daily dose of 20-60 mg omeprazole produces fast ulcer healing in almost all patients.