Methotrexate sodium is a chemotherapy drug that is used to treat various forms of cancer and autoimmune diseases. Some common synonyms for methotrexate sodium include MTX, Rheumatrex, Trexall, Amethopterin, and Methotrexate LPF. These different names are often used interchangeably and refer to the same medication. Methotrexate sodium works by preventing the rapid growth of cancer cells or cells that cause inflammation in autoimmune diseases. It is often prescribed in combination with other medications or therapies in order to maximize its effectiveness. Despite its potential side effects, methotrexate sodium is considered a valuable option for patients with these conditions.