Clarithromycin is a macrolide, if taken for 14 days, some patients may experience some gastrointestinal symptoms, adverse reactions of the nervous system, allergic reactions, as well as liver damage, kidney damage, etc. 1, gastrointestinal symptoms: Clarithromycin has the effect of contracting the smooth muscle of the gastrointestinal tract, some patients may experience nausea, vomiting, abdominal pain, diarrhea and other gastrointestinal adverse manifestations after taking it, some patients may also experience Some patients may also have symptoms such as abnormal taste and dry mouth; 2. Adverse reactions of the nervous system: usually transient, headache, insomnia, anxiety, depression, tinnitus, etc.; 3. Allergic reactions: manifested as allergic urticaria with itching; 4. Liver damage: because clarithromycin is directly metabolized in the liver, long-term excessive administration may cause damage to the liver and liver biochemical abnormalities. Patients may show general weakness, loss of appetite, aversion to oil and grease, etc.. However, they may also have no clinical symptoms and abnormalities are found when checking liver biochemistry; 5. Kidney damage: there may be an increase in blood creatinine concentration, and kidney function needs to be monitored. If patients need to take clarithromycin for 14 days, it is recommended to pay attention to the above adverse reactions and check liver biochemistry. Whether it is necessary to stop the drug or adjust the treatment plan should be judged by the doctor and follow-up treatment should be carried out under the guidance of the doctor.