Cyclophosphamide is a relatively common adverse reaction of this drug is the possibility of causing hemorrhagic cystitis, dysuria, frequent urination, painful urination and so on, so after the use of this drug must drink a lot of water, more urination, which is conducive to the metabolism of the drug discharge, but also to reduce the risk of urinary system adverse reactions. Cyclophosphamide is a relatively strong cytotoxic drug, mostly used in the treatment of malignant tumors, its adverse reactions are still relatively obvious, including bone marrow suppression, resulting in leukopenia, thrombocytopenia and other conditions. In addition, hemorrhagic cystitis may occur, as well as some central nervous system toxicity, and in a very small number of patients, abnormalities of liver and kidney function may also occur. Therefore, it is important to closely monitor the patient’s symptoms and laboratory test results following the use of this drug.