Ranitidine has the effect of inhibiting gastric acid secretion, reducing the activity of digestive enzymes in the stomach and side effects such as nausea and vomiting. Ranitidine is a histamine H₂ receptor antagonist with a long-lasting effect, which can inhibit the secretion of gastric acid and the activity of digestive enzymes in the stomach by blocking the binding of histamine to H₂ receptor. It is suitable for gastric ulcer, duodenal ulcer and other diseases. Side effects of Ranitidine commonly include nausea, vomiting, skin rash, etc. Mild hepatic impairment is seen in a few cases. It is contraindicated in people who are allergic to this drug, and in people with liver or kidney insufficiency. Prolonged use of this drug will reduce the absorption of vitamin B₁₂, need to pay attention to vitamin B₁₂ deficiency. Ranitidine has nausea, vomiting, rash and other side effects, it is recommended to use the drug under the guidance of a doctor, not blindly self-medication to avoid adverse effects.