The main side effects of Gefitinib are cough and acute attacks of dyspnea. Its main use is oral for the treatment of some locally advanced non-small cell lung cancer and so on. The side effects of Gefitinib mainly include acute attack or aggravation of pulmonary symptoms such as cough, dyspnea and fever; liver and kidney function impairment; eye symptoms and diseases such as dry eyes, keratitis and conjunctivitis; digestive symptoms such as nausea, vomiting and diarrhea. Gefitinib is mainly used for the treatment of locally advanced or metastatic non-small cell lung cancer with sensitive mutations in the epidermal growth factor receptor gene. Its recommended dosage is one tablet (250g) taken orally once a day. The use of specific drugs should be under the supervision of a doctor.