The main anti-tuberculosis drugs currently used in clinical practice are: the first-line drugs are bactericidal agents, commonly used drugs include isoniazid, rifampin, pyrazinamide, ethambutol, etc. The second-line drugs are bactericidal agents, and the commonly used drugs are para-aminosalicylic acid, aminothiourea, colistin, ethionamide, etc. The following is a brief description of the main side effects and precautions of these commonly used anti-tuberculosis drugs. Isoniazid The side effects are mainly peripheral neuritis, hepatic impairment, and occasionally seizures (due to central nervous system damage), which can be observed under normal circumstances. If neurological symptoms such as numbness or burning sensation in the distal extremities appear, vitamin B6 30-60 mg daily should be added to improve the symptoms. Liver function should be checked regularly while taking isoniazid, at least once every three months, to understand the status of liver function. If there is elevated transaminases, enzyme-lowering Chinese medicine such as Wu Wei Zi preparation should be given along with liver protection treatment. There is no need to stop the medicine for simple elevated transaminases. The common side effects of rifampin are digestive symptoms, such as loss of appetite, nausea, vomiting and diarrhea, etc. Jaundice and elevated transaminases may occur in patients with high doses or chronic hepatitis. Therefore, the dose of the drug should be strictly controlled. Patients with a history of hepatobiliary disease are prohibited from taking the drug, and liver function should be checked regularly when it is applied at regular doses. Rifampin has also been reported to cause acute renal failure and acute hemolysis, while rifapentine has milder adverse reactions than rifampin. Gastrointestinal reactions are rare. Influenza syndrome and immune platelet reduction have not been observed with this product, and no anaphylaxis-like reactions have been observed. If such adverse reactions occur, the drug must be discontinued promptly. In the clinical use of rifapentine, attention should be paid to whether the patient has a previous history of drug allergy; if the patient has a history of rifamycin allergy, the use of rifapentine should be absolutely prohibited. It is contraindicated in patients with severe hepatic insufficiency, biliary obstruction, and pregnant women. The use of rifapentine should be monitored for adverse reactions and treated promptly. Pyrazinamide side effects are rare, mainly liver damage, and can be seen in individual patients with large doses, daily doses of more than 2 grams or too long a course of treatment, and more often in the elderly. In order to prevent toxic reactions, the daily dose should be less than 2 grams and the course of treatment should be less than 3 months, and the drug should not be used for too long. Rare side effects include elevated blood uric acid and induced arthralgia, so people with gout qualities and gout patients should not use this drug. In addition, there are very individual sun-sensitive people, taking the drug can make the skin exposure area bright red-brown or bronze, after stopping the drug can gradually recover. Ethambutol has few side effects and is a high safety factor anti-tuberculosis drug. The drug can occasionally cause neuritis with prolonged administration, which is dose-related. Once numbness of the extremities occurs, vitamin B6 can be used to counteract it, which can improve the symptoms more quickly. Occasional retrobulbar optic neuritis can also be seen, usually at high doses, for which monthly checks of visual acuity, including visual acuity, color vision, visual field and fundus should be performed. The most common side effects are gastrointestinal symptoms, such as loss of appetite, nausea, vomiting, heartburn, pain in the upper abdominal region, abdominal distension and diarrhea. Individual patients who have been taking the drug for a long time (more than 2 months) may experience elevation of single transaminases, which may be accompanied by abdominal distension, poor appetite and nausea. The effects of capreomycin are similar to those of streptomycin, and the side effects are also similar to those of streptomycin, namely damage to the 8th pair of cranial nerves. The dose of the drug should not be large, and the duration of the drug should not be too long. The drug can be used with caution in patients with liver and kidney insufficiency because of the transient proteinuria and elevated transaminases when applied in large doses. Currently, this drug is used less frequently. Aminothiourea The side effects of aminothiourea are related to the dose size, less than 100 mg per day, but more than 100 mg and long-term application. The main side effects are gastrointestinal symptoms and liver damage, including loss of appetite, nausea, vomiting, constipation and elevated transaminases, and occasionally jaundice. When these clinical reactions occur, the dosage should be reduced appropriately, and the drug should be discontinued if the symptoms remain unresolved. In addition, a very small number of patients may experience bone marrow suppression and central nervous system reactions, progressive anemia, leukopenia, headache, dizziness, vertigo, ataxia and blurred vision, etc. When these serious reactions occur, the drug should be discontinued immediately. Ethionicotinamide side effects are common and widespread in the gastrointestinal tract. It is advisable to take the drug after meals and add sodium bicarbonate in appropriate amounts to reduce this reaction. The rare side effect is liver and kidney function damage, so patients with poor liver and kidney function need to be used with caution. Currently, ethylthioisonicotinamide is rarely used and is replaced by propylthioisonicotinamide. The latter has relatively fewer side effects and is safer.