When using afatinib for the treatment of lung cancer and other diseases, it is necessary to use the drug regularly according to the doctor’s prescription, and the treatment should not be interrupted unless drug resistance or serious adverse reactions occur. There is no literature or treatment guideline suggesting that afatinib can be used at one-day intervals in the treatment of some metastatic non-small cell lung cancer and other diseases, and it usually needs to be used continuously without pause in between. In case of serious adverse reactions such as severe hepatic impairment, cardiac impairment, interstitial lung disease, etc., the dosage of the drug can be cautiously lowered after evaluation by a physician, and if no relief can be achieved, it is necessary to discontinue the use of the drug. In addition, it should be noted that the drug is prohibited for allergic patients and children. It should be used with caution during pregnancy and lactation after strict evaluation, and it is recommended to stop breastfeeding during lactation. The drug is not recommended to be taken with food. The drug is prohibited to be shared with drugs such as rifampicin and carbamazepine. Afatinib needs to be used under the close supervision of a clinician, unauthorized use of the drug is absolutely prohibited.