methorexate psoriasis arthritis

I have been suffering from rheumathoid arthritis for a few years. Few weeks ago, I have been at my doctor and he wanted to change therapy I already had. Now he prescribed me methotrexate. I have heard this is medicine used for psoriasis so I am a little bit confused. Can you tell me something about this medicine, and is there any possibility my doctor misdiagnosed me or make mistake with choosing of medicine to treat my condition?

Methotrexate is classified as an antimetabolite drug, which means it is capable of blocking the cell’s metabolism. As result of this effect, it has been found helpful in treating certain diseases associated with abnormally rapid cell growth. This could be disease such as cancer of the breast and psoriasis. Recently, methotrexate has been shown to be effective in inducing miscarriage, for example in patients with ectopic pregnancy, because of its action of killing the rapidly growing cells of the placenta. It has also been found very helpful in treating rheumatoid arthritis. Anyway, I have to tell you that its mechanism of action in this illness is not known. It seems to work, in part by altering aspects of immune function, which may play a role in causing your rheumatoid arthritis as well. Methotrexate is used for cancer treatment generally in higher doses than for other uses, but this should not worry you. Beside all this, Methotrexate is used to treat psoriasis, an inflammatory skin disease, as well as the arthritis; I guess that is something you found confusing. If I were you, I would believe in your doctor’s diagnosis and take this medicine as he prescribed you.