Esomeprazole is in a class of drugs called proton pump inhibitors which block the production of acid by the stomach. Other drugs in the same class include omeprazole , lansoprazole , rabeprazole and pantoprazole. Chemically, esomeprazole is very similar to omeprazole. Esomeprazole, sold under the brand names Nexium among others, is a medication which reduces stomach acid. It is used to treat gastroesophageal reflux disease , peptic ulcer disease , and Zollinger–Ellison syndrome. Esomeprazole is a proton pump inhibitor (PPI). It works by reducing the amount of acid in the stomach which helps in relief of acid related indigestion and heartburn. Esomeprazole works by binding irreversibly to the H+/K+ ATPase in the proton pump. Inhibition dramatically decrease the secretion of hydrochloric acid into the stomach HOW NEXIUM WORKS Turns Off Acid Pumps. Proton pump inhibitors (PPIs) are effective treatments for acid reflux disease. They work by turning off some of the acid pumps in the stomach's acid-producing cells, reducing the amount of acid in the stomach. Esomeprazole is used to treat certain stomach and esophagus problems (such as acid reflux, ulcers). It works by decreasing the amount of acid your stomach makes. It's not known if esomeprazole works less well the longer you take it. If you feel like it isn't working any more, talk to your doctor. If you feel like it isn't working any more, talk to your doctor. Esomeprazole is in a class of medications called proton pump inhibitors. It works by decreasing the amount of acid made in the stomach. It works by decreasing the amount of acid made in the stomach. How should this medicine be used? Detailed Esomeprazole dosage information for adults and children. Includes dosages for Gastroesophageal Reflux Disease, Erosive Esophagitis, Duodenal Ulcer Prophylaxis and more; plus renal, liver and dialysis adjustments. 1. How it works. Esomeprazole reduces the production of stomach acid by irreversibly blocking the actions of an enzyme responsible for acid production, called H+/K+ ATPase (also known as the gastric proton pump).