Unlike the two classes of currently marketed over-the-counter heartburn treatments, antacids and acid reducers, Prilosec OTC is indicated for the treatment of heartburn that occurs two or more days per week (frequent heartburn). It stops acid production at its source in the stomach. Prescription Prilosec is currently widely prescribed for frequent heartburn and other related, but more serious, problems that need the care of a physician. Antacids and acid reducers, which have long been available over-the-counter, are used for the relief of acute heartburn symptoms. Acid reducers are additionally used for the prevention of meal-induced heartburn.