The current medications used for the treatment of MS-associated fatigue such as amantadine hydrochloride and pemoline are useful to some, but not all patients. In a multicenter trial (2) it was found that 100 mg amantadine twice daily significantly improves fatigue. Pemoline in a placebo-controlled trial (3) failed to show significant effect on fatigue in MS patients and was poorly tolerated as side effects occurred in 25% of patients. A third trial (4) compared pemoline to amantadine and placebo, and showed only a positive trend for pemoline, while amantadine had a benefit over placebo in some fatigue measures. There was also a marked placebo effect in this trial, with approximately half of patients reporting improvement in fatigue no matter what treatment (pemoline, amantadine or placebo) they were taking.