I'm not familiar with it but found some info.


http://en.wikipedia.org/wiki/Methotrexate

Methotrexate (rINN) ( /mɛθɵˈtrɛkseɪt/), abbreviated MTX and formerly known as amethopterin, is an antimetabolite and antifolate drug. It is used in treatment of cancer, autoimmune diseases, ectopic pregnancy, and for the induction of medical abortions.[1] It acts by inhibiting the metabolism of folic acid. Methotrexate began to replace the more toxic antifolate aminopterin starting in the 1950s. The drug was developed by Yellapragada Subbarao.

It is used as a treatment for some autoimmune diseases, including rheumatoid arthritis, psoriasis, psoriatic arthritis, lupus and Crohn's disease, to name a few. Although methotrexate was originally designed as a chemotherapy drug (in high doses), in low doses methotrexate is a generally safe and well tolerated drug in the treatment of certain autoimmune diseases. Because of its effectiveness, low-dose methotrexate is now first-line therapy for the treatment of rheumatoid arthritis.

http://www.rheumatology.org/practice...thotrexate.asp