Omeprazole is a proton pump inhibitor that is used to treat symptoms of gastroesophageal reflux disease and other conditions caused by excess stomach acid. Omeprazole delayed-release capsules, USP are indicated for short-term treatment of active duodenal ulcer in adults. Most patients heal within four weeks. Some patients may require an additional four weeks of therapy. Omeprazole, sold under the brand names Prilosec and Losec among others, is a medication used in the treatment of gastroesophageal reflux disease (GERD), peptic ulcer disease, and Zollinger–Ellison syndrome. [1] Omeprazole delayed-release capsules in combination with clarithromycin and amoxicillin, is indicated for treatment of patients with H. pylori infection and duodenal ulcer disease (active or up to 1-year history) to eradicate H. pylori in adults. Find patient medical information for Omeprazole (Prilosec, Prilosec OTC) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings Omeprazole is used to treat certain conditions where there is too much acid in the stomach. It is used to treat gastric and duodenal ulcers, erosive esophagitis, and gastroesophageal reflux disease (GERD). Omeprazole, approved by the FDA, is available as a prescription and over-the-counter (OTC) drug used as a treatment for frequent heartburn. Learn about side effects, drug interactions, dosages, warnings, and more. What is this medication? OMEPRAZOLE (oh ME pray zol) is used to treat heartburn, stomach ulcers, reflux disease, or other conditions that cause too much stomach acid. It works by reducing the amount of acid in the stomach. It belongs to a group of medications called PPIs. Omeprazole (Prilosec) is a proton pump inhibitor that reduces stomach acid. It’s available both over the counter and with a prescription. Common omeprazole side effects include headaches and stomach-related side effects, such as nausea, vomiting, or diarrhea. Learn about the side effects of omeprazole, from common to rare, for consumers and healthcare professionals.