1.What is drugogenic lung disease? Clinically, drug-induced lung damage is more common. Drug-induced systemic adverse reactions are about 10-20%, of which drugogenic lung disease accounts for about 5-8%. More than 300 drugs are known to cause lung damage, including anti-microbials, anti-inflammatory drugs, chemotherapeutic oncology drugs, cardiovascular drugs, and banned substances. In recent years, it has been found that some biological agents can also cause diffuse lung damage, for example, interferon can cause nodular disease and occlusive fine bronchitis, immunoglobulin and anti-thymocyte globulin may cause pulmonary edema, gefitinib can cause interstitial pneumonia, and growth factors can cause acute respiratory distress syndrome and severe interstitial lung disease. Ye Suyi, Department of Respiratory and Critical Care Medicine, Beijing Chaoyang Hospital 2. Why is it difficult to diagnose drugogenic lung diseases? First, there are differences in the diagnostic techniques used. Compared with chest X-ray, HRCT can detect lung lesions more sensitively, and if chest X-ray is used as the standard for diagnosis, the occurrence of drugogenic lung disease may be underestimated. Second, drug-related lung disease is not easily diagnosed early, especially when there are no symptoms; again, it is difficult to accurately determine the relationship between drugs and lung damage in oncology patients who develop drug-related lung disease. 3. Can drug-related lung disease be predicted? There is a lack of a necessary link between the dose, duration of therapy and pulmonary toxicity of most drugs, and the occurrence of drugogenic lung disease is often unpredictable and varies individually. Drugogenic lung disease is difficult to predict and may include the following risk factors: (1) previous respiratory response to the drug; (2) occupational effects on the respiratory system; (3) underlying disease at the time of drug therapy, such as ulcerative colitis or rheumatoid arthritis, which may exacerbate respiratory symptoms; (4) individual differences in the occurrence of drug side effects; (5) interactions between combined drugs, several drugs with pulmonary (5) interactions between combined medications, several drugs with pulmonary toxicity may enhance pulmonary toxicity; (6) the effect of the mode of administration. 4. What are the histopathological types of lung disease in drugogenic lung disease? There are different histopathological types of drugogenic lung disease, including interstitial lung disease, pulmonary edema, pulmonary hemorrhage, airway disease, pleural changes, vascular lesions, mediastinal lesions, large airway involvement, muscular and neurological involvement, and systemic symptoms. Among the histopathological types of interstitial lung disease include granulomatous interstitial pneumonia, pseudonodular disease, nonspecific interstitial pneumonia, eosinophilic pneumonia, mechanized pneumonia, desquamative interstitial pneumonia, lymphocytic interstitial pneumonia, common interstitial pneumonia, acute interstitial pneumonia, subclinical alveolitis, alveolar protein deposition-like changes, pulmonary iron-containing flavin deposition, diffuse alveolar injury, etc. Different drugs may cause the same histopathological changes in lung damage with similar clinical manifestations; one drug can also cause lung injury with multiple pathological types. Some pharmacogenic lung diseases may also be part of the systemic side effects caused by drugs, such as drug-induced allergic syndrome, in addition to lung damage, but also accompanied by brain, digestive system, liver, bone marrow and other organ involvement, etc. 5.What are the clinical manifestations of drugogenic lung disease? The symptoms are not specific. Initially, it manifests as exertional dyspnea, and as the disease progresses, dyspnea appears in the quiet state. Other symptoms include dry cough, and systemic symptoms such as fever and malaise. On auscultation, bursting sounds in both lower lungs may be heard, as well as occasional rales, dry sounds or wet rales. In some cases, there are no positive signs in the lungs. Pestle fingers are seen in patients with pulmonary fibrosis. 6. Do I need a bronchoscopy for drugogenic lung disease? Bronchoscopy, transbronchial lung biopsy (TBLB) and bronchoalveolar lavage fluid (BALF) should be considered in patients with suspected drugogenic lung damage. The combination of clinical and imaging changes can help in the diagnosis and differential diagnosis of drugogenic lung damage. 7.What are the imaging manifestations of drugogenic lung disease? The characteristics and distribution of imaging in patients with drugogenic lung disease are diverse. For example, amiodarone pneumonia shows asymmetric non-stage blurred shadows, migrating solid shadows are seen in mechanized pneumonia, ground glass shadow and mosaic sign are seen in desquamative interstitial pneumonia, symmetric lobular septal thickening and foveal shadow under the pleura of both lower lungs are seen in interstitial pneumonia and pulmonary fibrosis. 8.How to treat drug-related lung disease? First, the drug should be discontinued in a timely manner. Most drug-related lung diseases are reversible, or the disease no longer progresses. If the lung damage is severe, glucocorticoids can be added according to their possible histopathological changes. Experimental re-administration of suspicious drugs is generally not advocated to avoid further damage to the lungs.