Omeprazole enteric-coated capsules belong to proton pump inhibitors and are mainly used for the treatment of gastric ulcers, duodenal ulcers, stress ulcers, reflux esophagitis, and Dreh-Eltzinger syndrome (gastrinoma). Combined with amoxicillin and clindamycin or with metronidazole and clarithromycin, it can be used for the eradication treatment of Helicobacter pylori infection. Omeprazole enteric-coated capsule can combine with the ATPase of the gastric mucosal wall cells and inhibit the activity of the enzyme, thus the gastric mucosal wall cells’ secretion of gastric acid is inhibited. Adverse reactions to the drug include mild nausea, vomiting, bloating, constipation, diarrhea, abdominal pain, headache, drowsiness, insomnia, and peripheral neuritis. Prolonged application of omeprazole can lead to vitamin B₁₂ deficiency or the development of gastric carcinoids, among others. Omeprazole is contraindicated in people who are allergic to omeprazole, in people with severe renal insufficiency, in infants and young children, in pregnant women and in breastfeeding women. The drug is enteric-coated tablets should not be chewed, so as not to destroy the efficacy of the drug. Patients need to strictly follow the doctor’s instructions when using the drug, if you feel uncomfortable in the process of taking the drug, you should immediately stop the drug and consult a doctor.