Esomeprazole is a drug used in the treatment of conditions caused by excessive production of stomach acid. Conditions such as duodenal ulcers, gastroesophageal reflux disease, erosiveesophagitis, dyspepsia and Zollinger-Ellison syndrome are all treated with Esomeprazole. It belongs to a class of drugs known as proton-pump inhibitors, meaning that it stops acid production in the parietal cells of the stomach. These cells pump out protons, or hydrogen ions, and these ions go toward producing hydrochloric acid. However, it is worth noting that this drug is not used for those who experience immediate symptoms of heartburn, and only used for those with a proven underlying long-term condition.