Afatinib is a kind of targeted drug for the treatment of lung cancer, pay attention to the time of taking the drug, avoid light as much as possible, have regular checkups, and consult the doctor in time when serious adverse reactions occur. 1. Patients may have diarrhea after taking the drug, if serious diarrhea or persistent diarrhea occurs, it is necessary to consult a doctor in time. 2. Patients should minimize exposure to sunlight while taking the drug, and report to a doctor immediately if skin symptoms such as erythema, acne-like rash, or severe blisters, blisters, or exfoliative skin lesions occur. 3. Patients taking the drug should regularly review the CT of the lungs, if symptoms of interstitial lung disease, pneumonia or acute respiratory distress syndrome occur, they should consult a doctor promptly. 4. This drug may cause stomatitis, onychomycosis, dry skin, itchy skin or loss of appetite. 5. This drug has hepatotoxicity, a small number of patients may occur liver injury, during the drug need to regularly test liver function, such as liver function is seriously impaired may need to stop the drug. 6. Symptoms of left ventricular insufficiency, such as dyspnea, physical intolerance, peripheral edema, and palpitations, may occur during drug administration. 7. Patients may experience symptoms of keratitis, including eye pain, eye inflammation, tearing, light sensitivity, and vision changes. 8. Female patients who are pregnant or breastfeeding should not use this drug. If not pregnant, reliable contraception should be used to prevent pregnancy for at least 2 weeks after discontinuation of the drug. 9. Patients should take the drug at least 1 hour before or 2 hours after meals. 10. If a dose is missed, patients are advised to make up the missed dose as soon as possible, but if the next dose is within 12 hours, the missed dose will be skipped. Afatinib should be taken under the supervision of a doctor.