I have multiple sclerosis, should i take tysabri (natalizumab)? for my medication

Complex : Tysabri (natalizumab) is the most effective medication currently on the market, but has a risk of a bad infection "pml". If you are having progressive problems, such as relapses, or your MRI studies show more lesions, you may well need more potency, especially if you are taking Avonex or copaxone. But all ms pts are different, and a variety of choices are present. An ms specialist can help.

Maybe: Tysabri (natalizumab) is a highly effective, once-monthly IV therapy for relapsing forms of ms. It is generally used as a second or third line treatment due to the risk of a rare brain infection. However, depending on how your ms is acting, the risk may well be worth it in order to control your disease. This is a decision between you and your treating neurologist. Discuss concerns with him/her.