Fatigue Treatment Using Provigil in Patients With Relapsing Remitting Multiple Sclerosis

Multiple sclerosis and fatigue Fatigue is one of the most common symptoms of multiple sclerosis (MS), occurring in 30%-80% of patients and for many of them fatigue is the most disabling symptom (1).

Definition of fatigue according to the MS Council for Clinical Practice Guidelines is as follows: "A subjective lack of physical and/or mental energy that is perceived by the individual or caregiver to interfere with usual and desired activities".

As fatigue is a subjective and non-specific symptom, and can easily be confused with either weakness or depressed mood, both common in MS, the following characteristics have been defined to better diagnose MS-associated fatigue:

• MS-related fatigue generally occurs on a daily basis.
• It tends to worsen as the day progresses.
• It tends to be aggravated by heat and humidity.
• It is not directly correlated with either depression or the degree of physical impairment.
• It may occur first thing in the morning even if the patient has had a restful full night's sleep.

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.