Omeprazole enteric capsules are well tolerated and adverse reactions may include: 1. Digestive system: dry mouth, mild nausea, vomiting, abdominal distension, constipation, diarrhea, abdominal pain, etc.; alanine aminotransferase (ALT), aspartate aminotransferase (AST) and bilirubin may be elevated, which are generally mild and transient and mostly do not affect treatment. In addition, foreign data reported that gastric mucosal cell hyperplasia or atrophic gastritis can be observed in gastric body biopsy specimens of patients treated with omeprazole for a long time. 2. Neuropsychiatric system: abnormal sensation, dizziness, headache, drowsiness, insomnia, peripheral neuritis, etc. may be observed. 3.Metabolic/endocrine system: long-term application of omeprazole may lead to vitamin B12 deficiency. 4.Other: There may be rash, gynecomastia, hemolytic anemia, etc. The manifestations of overdose include: 1. blurred vision, confusion, sweating, drowsiness, dry mouth, flushing of the face, headache, nausea, tachycardia or arrhythmia, etc. 2. Treatment of overdose: mainly symptomatic and supportive treatment. Omeprazole is not easily dialyzed and should be dealt with immediately in case of accidental overdose.