Prilosec is used in adults for the short-term treatment of active ulcers of the duodenum, active benign gastric ulcers, gastroesophageal reflux disease (GERD, or stomach contents rising back into the food pipe), and erosive inflammation of the esophagus. This medicine is also used for the long-term treatment of conditions that increase gastric acid secretion (eg, Zollinger-Ellison syndrome). This medicine can also be used in combination with other medicines to treat and eliminate H. pylori infection and associated active ulcers of the duodenum.