Used as a antineoplastic and antirheumatic. A folic Acid antagonist.

     Methotrexate is used to treat certain types of cancer or to control severe psoriasis or rheumatoid arthritis that has not responded to other treatments. It may also be used to control juvenile rheumatoid arthritis. Methotrexate belongs to a class of drugs known as antimetabolites. It works by slowing or stopping the growth of cancer cells and suppressing the immune system.

cytotoxicity, it can be used in conjunction with calcium leucovorin. It is primarily used for the treatment of acute leukemia (acute lymphocytic leukemia), breast cancer, malignant mole and choriocarcinoma, head and neck cancer, bone cancer, leukemia, spinal cord meningeal infiltration, lung cancer, reproductive system cancer, liver cancer, refractory psoriasis vulgaris, dermatomyositis, body myositis, ankylosing spondylitis inflammation, Crohn's disease, psoriasis and psoriatic arthritis, Behcet's disease and autoimmune disease. In Rheumatic Arthritis:
     Methotrexate is an immunosuppressant and can be used for easing the process of rheumatism with a particularly excellent efficacy in treating synovial inflammation of rheumatoid arthritis and is the most frequently used drugs for treating rheumatoid diseases.

    Methotrexate (MTX), is one of first line DMARDs(disease-modifying antirheumatic drugs).The order of agent selection is not clearly defined, but MTX is often chosen initially because long-term data suggest superior outcomes compared with other DMARDs and lower cost than biologic agents.

   MTX inhibits cytokine production and purine biosynthesis, which may be responsible for its antiinflammatory properties. Its onset is relatively rapid (as early as 2 to 3 weeks), and 45% to 67% of patients remained on it in studies ranging from 5 to 7 years.

Toxicities are GI (stomatitis, diarrhea, nausea, vomiting), hematologic (thrombocytopenia, leukopenia), pulmonary (fibrosis, pneumonitis), and hepatic (elevated enzymes, rare cirrhosis). MTX is contraindicated in pregnant and nursing women, chronic liver disease, immunodeficiency, pleural or peritoneal effusions, leukopenia, thrombocytopenia, preexisting blood disorders, and creatinine clearance <40 mL/min.
    Early treatment of rheumatoid arthritis with more aggressive therapy such as methotrexate helps to reduce further joint damage and to preserve joint function.

    It is used to treat cancer, autoimmune diseases, ectopic pregnancy, and for medical abortions. Types of cancers it is used for include breast cancer, leukemia, lung cancer, lymphoma, and osteosarcoma.Types of autoimmune diseases it is used for include psoriasis, rheumatoid arthritis, and Crohn's disease.