Both drugs belongs to class known as proton pump inhibitors (PPI) which block the production of acid by the stomach. Proton pump inhibitors are used for the treatment of conditions such as ulcers, gastroesophageal reflux disease (GERD) and Zollinger-Ellison syndrome that are caused by stomach acid. These drugs blocks the enzyme in the wall of the stomach that produces acid. By blocking the enzyme, the production of acid is decreased, and this allows the stomach and esophagus to heal.