When injecting docetaxel, dexamethasone, 16 mg daily for at least 3 days, is usually required one day prior to docetaxel titration to prevent allergic reactions and fluid retention. Docetaxel is a paclitaxel antitumor agent that acts as an antitumor agent by interfering with the network of microtubules necessary for cellular function during mitosis and interphase. Docetaxel is indicated for the treatment of advanced or metastatic breast cancer that has failed prior chemotherapy; and advanced or metastatic non-small cell lung cancer that has failed cisplatin-based chemotherapy. Docetaxel can only be used intravenously. Pre-administration of a glucocorticoid, such as dexamethasone, is required prior to receiving docetaxel treatment to reduce the incidence and subseverity of fluid retention as well as to reduce the severity of an allergic reaction, which is initiated one day prior to the injection of docetaxel and is given at 16 mg daily for 3 days. Docetaxel may cause adverse reactions such as flushing, bronchospasm, generalized rash erythema, and severe hypotension. Contraindicated in persons with a history of severe hypersensitivity to docetaxel; white blood cell count <1500 cells/mm³; severe impairment of liver function. Precautions: appropriate emergency facilities should be available during the injection period, the main functional indicators should be closely observed, and it must be used under the guidance of a doctor who has experience in the application of cancer chemotherapeutic drugs. It is recommended to follow the doctor's instructions for injection of docetaxel to avoid adverse consequences.