Esomeprazole is a proton pump inhibitor (brand name Esprol) which reduces stomach acid secretion through inhibition of the H+ / K+ ATPase in the parietal cells of the stomach. By inhibiting the functioning of this transporter, the drug prevents formation of stomach acid.

It is used in the treatment of dyspepsia, peptic ulcer disease, gastroesophageal reflux disease, and Zollinger-Ellison syndrome.