Omeprazole is a medicine that reduces the amount of acid in your stomach. It's used to treat conditions such as heartburn. You can buy some types from pharmacies and shops, but most types are only available with a prescription. Omeprazole is used to treat conditions that appear in the patient having too much stomach acid. This medication is available over-the-counter and in stronger doses via prescription. Omeprazole, approved by the FDA, is available as a prescription and over-the-counter (OTC) drug used as a treatment for frequent heartburn. Heartburn is a very common symptom caused by acid reflux. Omeprazole, omeprazole/sodium bicarbonate is a proton pump inhibitor drug (PPI) prescribed for the treatment of ulcers, gastroesophageal reflux disease (GERD), Zollinger-Ellison syndrome, duodenitis, erosive esophagitis, heartburn, and H. pylori infection. Prilosec (omeprazole) is used to treat symptoms of GERD and other conditions caused by excess stomach acid. Includes Prilosec side effects, interactions and indications. Omeprazole is a medication that reduces the amount of acid in your stomach. It treats heartburn, stomach ulcers and reflux disease. 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). 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 a proton pump inhibitor that is used to treat symptoms of gastroesophageal reflux disease and other conditions caused by excess stomach acid. 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].