Methotrexate is an antimetabolic chemotherapeutic drug, methotrexate is currently clinically used in the treatment of acute leukemia, as well as squamous carcinoma of the head and neck, breast cancer, lung cancer and other solid tumors, methotrexate after the application of the main side effects are as follows: 1, bone marrow suppression, this is a common adverse reaction after the application of methotrexate, the adverse reaction affects the dosage of methotrexate, clinically, mainly in the form of white blood cells, Platelets, hemoglobin indicators decreased; 2, gastrointestinal reactions, which is also a common toxic side effects after the application of methotrexate, mainly manifested as nausea, vomiting, diarrhea, oral ulcers, and so on, and some will have the clinical manifestations of gastritis; 3, hepatic impairment, many methotrexate applicants are susceptible to cause hepatic impairment, and serious chronic hepatic fibrosis can occur.