Find Gastrointestinal Remedies at Target.com! Treats the same symptoms as Prescription Strength Prilosec OTC. Up & up Omeprazole delayed release tablets 20 mg is a proton pump inhibitor (PPI), the newest class of heartburn medications. PPIs deactivate the pumps in the stomach lining from producing acid, significantly inhibiting acid production (and its overproduction) at the source. PPIs are available over-the-counter or as a prescription to treat ulcers, gastroesophageal reflux disease (GERD) and erosive esophagitis. PPIs treat frequent heartburn that occurs two or more days per week. These products may take 1 to 4 days to work initially and are not indicated for immediate.