The pharmacology of esomeprazole and its role in gastric acid related diseases.

Esomeprazole (S-isomer of omeprazole) demonstrates a better pharmacokinetic/pharmacodynamic profile than the racemic product omeprazole. Esomeprazole's pharmacological activity of gastric acid secretion is through proton pump inhibition. The pharmacokinetic properties provide for an enhanced pharmacological effect. Esomeprazole is rapidly absorbed and the extent of absorption is higher resulting in higher systemic absorption of esomeprazole (bioavailability), which coupled with reduced clearance results in greater systemic exposure. This pharmacodynamic profile then provides for a prolongation of inhibition of gastric acid output and correlates well with its more beneficial therapeutic efficacy over omeprazole and some of the other proton-pump inhibitors. It has been well proven as an effective agent in the treatment of gastro-esophagitis reflux disease, (reflux esophagitis and non-erosive reflux disease), NSAID-induced gastric-intestinal symptoms and ulcers, Helicobacter pylori infection and Zollinger-Ellison syndrome. Esomeprazole has a good tolerability profile and a low potential for drug interaction.