Summary

Methotrexate, a folate analog antimetabolite, is one of the oldest cytotoxic drugs still in use. It is active against a variety of malignancies including bladder and breast cancer, head and neck tumors, gestational choriocarcinoma, osteogenic sarcoma, lymphomas, and leukemias.

Methotrexate is given mostly intravenously (IV), usually at standard doses (milligrams). It can also be delivered in much higher doses (grams), which is known as high-dose methotrexate (HDMTX). The intrathecal (IT) route is used particularly in children with acute lymphoblastic leukemia (ALL) and in adults with meningeal carcinomatosis. The drug may be administered orally as well, mainly in non-oncological conditions such as rheumatoid arthritis and other autoimmune diseases.