Breast cancer infusion trastuzumab, do not need to take dexamethasone, should pay attention to adjusting the infusion rate, after the drug should be regularly recheck the heart function. Breast cancer HER-2 positive patients, you can use trastuzumab injection targeted drug therapy, the drug does not need pretreatment, do not need to take dexamethasone before using the drug. The use of trastuzumab injection is divided into the initial loading dose, as well as the maintenance dose, the first use should be controlled for 90 minutes intravenous drip, observe whether there is fever, chills and other reactions. If there is no adverse reaction to initial use, the maintenance dose can be titrated intravenously over 30 minutes. Trastuzumab has the potential to cause adverse reactions in the heart, causing a decrease in ejection fraction, which in severe cases can lead to congestive heart failure, and regular ECGs and cardiac ultrasounds should be performed during the medication period to assess cardiac function. Breast cancer patients should use trastuzumab under the guidance of an experienced physician, and the occurrence of adverse reactions promptly treated.