There is no difference between Losec and Omeprazole, they are the same drug, Losec is the trade name and Omeprazole is the generic name. Omeprazole is a proton pump inhibitor that inhibits the secretion of gastric acid and pepsin in the patient’s body, but does not alter the blood flow to the gastric mucosa. The drug is used in gastroesophageal reflux disease, bleeding peptic ulcers, stress, and acute gastric mucosal injury caused by NSAIDs. Adverse reactions include headache, abdominal pain, nausea, diarrhea, vomiting and flatulence. It is contraindicated in those who are allergic to the product, those with severe renal insufficiency and infants. Note that it should not be combined with nelfinavir and atazanavir. It is recommended that patients go to the hospital in time, follow the doctor’s instructions for medication, not self-medication.