Use of Amantadine for Chronic Fatigue Syndrome

Fatigue is a chronic and debilitating hallmark of the chronic fatigue syndrome, which is often accompanied by sleep disturbances, myalgias, and depression. ^1,2 This condition has been reported worldwide, and case definitions have been developed by the Centers for Disease Control and Prevention. ³ Amantadine hydrochloride has been used to treat fatigue associated with conditions such as multiple sclerosis. ^4-6 We investigated the symptomatic effects of amantadine on 4 patients with chronic fatigue syndrome using a multiple single-subject trial design. ⁷ Patients who had a diagnosis of chronic fatigue made by their family physicians and who fulfilled the criteria for chronic fatigue syndrome defined by the Centers for Disease Control and Prevention were included. ³ Using a multiperiod, crossover design, ⁸ with a single subject for each sequence, patients received either placebo (B) or amantadine hydrochloride (A), 100 mg twice daily. Patients were blinded to treatment identification.