Prilosec is a proton pump inhibitor that decreases the amount of acid produced in the stomach.
Prilosec is used to treat symptoms of gastroesophageal reflux disease (GERD) and other conditions caused by excess stomach acid. Omeprazole is also used to promote healing of erosive esophagitis (damage to your esophagus caused by stomach acid). Prilosec may also be given together with antibiotics to treat gastric ulcer caused by infection with helicobacter pylori (H. pylori).