Herceptin is the trade name, generically known as trastuzumab, side effects include cardiac insufficiency, infusion reactions, embryotoxicity, and exacerbation of neutropenia. Paget is the trade name, generically known as patulizumab, and the side effects include adverse skin, gastrointestinal, hematologic, and other systemic reactions. The side effects of trastuzumab include cardiac insufficiency, infusion reactions, embryotoxicity, chemotherapy-induced neutropenia exacerbation, and pulmonary reactions. Breast cancer patients may develop fever, nausea and vomiting, diarrhea, headache, malaise, respiratory distress, rash, and neutropenia. Gastric cancer patients may experience neutropenia, diarrhea, fatigue, anemia, weight loss, and upper respiratory tract infection. Side effects of patozumab include fatigue, mucosal inflammation, weakness; skin disorders such as alopecia, rash; gastrointestinal disorders such as diarrhea, nausea, vomiting; hematologic disorders such as neutropenia, anemia; neurologic disorders such as dizziness, headache; in addition to myalgia, decreased appetite. In severe cases, there are left ventricular dysfunction, embryo fetotoxicity, infusion-related reactions and allergic reactions. Patients should closely monitor the corresponding indicators in the course of medication, and should consider reducing or stopping the drug once there is any abnormality, and adjust the treatment program in time.