Pantoprazole is a proton pump inhibitor (PPI) used in the treatment of heartburn, gastroesophageal reflux disease (GERD), and peptic ulcer disease. Pantoprazole reduces the amount of acid produced by your stomach. Loss of gastric acid can lead to heartburn and damage to the esophagus. In addition, patients may also experience other unpleasant symptoms, including upper abdominal pain, which may be relieved by taking a PPI such as pantoprazole.