Methotrexate is an anti-folate antitumor drug, which mainly inhibits the growth and reproduction of tumor cells by inhibiting dihydrofolate reductase, which prevents the normal conversion of dihydrofolate into tetrahydrofolate, thus blocking the synthesis of DNA and RNA. Methotrexate is mainly used clinically for the treatment of various types of acute leukemia, especially acute lymphoblastic leukemia, malignant lymphoma, non-Hodgkin’s lymphoma and myxoid granuloma, multiple myeloma, head and neck cancer, lung cancer, various soft tissue sarcomas, breast cancer, ovarian cancer, cervical cancer, malignant staphyloma, choriocapillaris, testicular cancer and psoriasis. Common adverse reactions to methotrexate include sore throat, nausea, vomiting, abdominal pain, diarrhea, gastrointestinal bleeding, and loss of appetite. In high dose applications, hematuria, proteinuria, oliguria, azotemia, and even uremia can occur.