* powerful immunosuppressive medication - rarely used

    * chemotherapy agent

    * for secondary progressive, progressive relapsing, and some

       types of relapsing-remitting MS

    * reduces relapses and lengthens time between relapses

    * IV infusion once every three months

    * side effects: risk of heart muscle injury (5%) and leukemia (1%)

    * nausea, hair loss, menstrual disorders (permanent menopause)

    * improvement compared to other treatments

    * approved in 2000