A healthcare provider may prescribe Prilosec^® (omeprazole) to treat several conditions associated with the esophagus, stomach, and intestines. The prescription drug works by blocking the acid production sites in the stomach, decreasing the amount of acid produced. Prilosec comes in a capsule form and is taken by mouth once or twice a day. The dosage of Prilosec your healthcare provider prescribes will vary depending on several factors, such as your age, the medical condition being treated, other medical conditions you may have, and other medications you may be taking.