When a second generation targeted drug has side effects, if the symptoms are mild you can continue to take the drug and give symptomatic treatment for the side effects. If the side effects are severe, it is recommended to stop taking the drug and give symptomatic treatment. Common side effects of second-generation targeted drugs include nausea, vomiting, allergy, bloating or skin lesions. For mild gastrointestinal discomfort, the gastrointestinal function can be improved by taking montelukast or amoxicillin. In case of drug allergy, it can be treated by reducing the dose of the drug or taking anti-allergy drugs such as diphenhydramine and paracetamol. Skin lesions or rashes can be treated by applying topical erythromycin ointment. If side effects result in serious complications such as angina pectoris, dyspnea or immune system damage, it is recommended to stop the medication and consult a doctor to adjust the treatment by changing the targeted drug. Since serious complications are not conducive to the treatment of the primary disease and can damage the health, it is not recommended to continue to take the drug without authorization. When choosing second-generation targeted drugs for radiotherapy, it is necessary to observe the drug reaction and regularly monitor the treatment results.