A randomized controlled trial of amantadine in fatigue associated with multiple sclerosis. The Canadian MS Research Group. Amantadine treatment of fatigue associated with multiple sclerosis. Fatigue therapy in multiple sclerosis: results of a double-blind, randomized, parallel trial of amantadine, pemoline, and placebo. A double-blind, placebo-controlled trial of amantadine for the treatment of fatigue in patients with the post-polio syndrome. Amantadine therapy for fatigue in multiple sclerosis.
One hundred and fifteen patients with definite multiple sclerosis (M.S.) and chronic persistent fatigue were studied. This ten-week cross-over study consisted of a 2-week baseline period and two 3-week treatment periods separated by a 2-week washout. Patients received either amantadine 100 mg bid or matching placebo capsules. Fatigue, the effect of fatigue on an individually pre-selected activity and its effect on activities of daily living, were evaluated. Amantadine produced a small but statistically significant decrease in fatigue. An important placebo effect was noted. Mean fatigue during the washout period was lower than during the placebo run-in period, independently of which treatment had been given first. Side effects were numerous both on amantadine and on placebo. Only insomnia was significantly more common with amantadine. Fatigue is a common symptom of multiple sclerosis (MS) that is without an effective treatment. A double-blind, controlled study of fatigue treatment was conducted to evaluate the efficacy of amantadine hydrochloride in treating MS-associated fatigue. Since fatigue cannot be characterized by a single symptom or behavior, a variety of neuropsychological, behavioral, and self-report measures were used to monitor changes across different systems. According to patients' daily diary ratings, amantadine produced small but statistically significant improvements in fatigue across four of seven dimensions (overall energy level, concentration, problem solving, and sense of well-being). In addition, patients with MS who were taking amantadine performed slightly better on the Stroop Interference Test, an attentional measure of freedom from distracting information. Although retrospective reports by patients with MS did not confirm the degree of improvement recorded on a daily basis, the study's results suggested that amantadine may offer modest benefits in alleviating the day-to-day subjective experience of fatigue. To determine the relative efficacy of amantadine, pemoline, and placebo in treatment of multiple sclerosis (MS)-related fatigue.
                Fatigue is a complication of MS. Both pemoline and amantadine have been used to treat MS fatigue, but their relative efficacy is not known.
                Amantadine, pemoline, and placebo were compared in a randomized, double-blind, placebo-controlled study using a parallel-group design. Ninety-three ambulatory MS patients completed the study. Primary outcome measures were the fatigue severity scale (FSS); the MS-specific fatigue scale (MS-FS); and subjective response determined by verbal self-report. Secondary outcome measures consisted of assessments of sleep, depression, and vitality. Repeated-measures analysis of variance with planned post-hoc contrasts and Fisher's exact test were used to compare treatment response.
                Amantadine-treated patients showed a significantly greater reduction in fatigue, as measured by the MS-FS, than did patients treated with placebo (p = 0.04). By verbal report at the end of the study, 79% of patients treated with amantadine versus 52% treated with placebo and 32% treated with pemoline preferred drug therapy compared with no treatment (p = 0.03). No significant differences in any primary outcome measures were noted between pemoline and placebo. Neither amantadine nor pemoline affected sleep or depression relative to placebo.
                Amantadine was significantly better than placebo in treating fatigue in MS patients, whereas pemoline was not. The benefit of amantadine was not due to changes in sleep, depression, or neurologic disability. Because amantadine has been shown to reduce fatigue in patients with multiple sclerosis, we performed a double-blind, placebo-controlled study to assess its efficacy in the disabling symptom of post-polio fatigue. Twenty-three patients completed six weeks of therapy. Fatigue was measured by the patients using visual analogue scales (twice per day) and numerical fatigue severity scales (once per week) and by overall impression (at end of therapy). Formal neuropsychological testing and serum drug levels were performed to assess compliance. On all measures, no significant difference was found between treatment and placebo groups. Fifty-four percent of patients given amantadine and 43% given placebo reported a decrease in fatigue; however, the visual analogue scales and fatigue severity scales failed to reflect any improvement. Several patients in the treatment group elected to continue amantadine therapy after the study was completed. Our findings suggest that amantadine is not significantly better than placebo in reducing the sensation of fatigue in post-polio syndrome, and that the measures we employed were insensitive to capture the subjective response experienced by a few patients. We carried out a double blind control study of fatigue in 32 patients with multiple sclerosis, comparing amantadine hydrochloride 100 mg twice a day and placebo. On amantadine 31% had marked improvement; 15.6% moderate improvement; 15.6% mild improvement; and 36.5% unchanged. On placebo, none noted marked improvement; one claimed moderate improvement on either amantadine or placebo. 18.7% reported mild improvement on placebo; and most of them had similar or more response to amantadine. No patient selected placebo over amantadine at the end of the trial. Overall improvement was seen in 62.5% of patients on amantadine and 21.8% on placebo. Additional experience up to two years suggests continued benefit but common and important side-effects.
The efficacy of amantadine in reducing fatigue in people with MS is poorly documented, as well as its tolerability. It is advisable to: (1) improve knowledge on the underlying mechanisms of MS-related fatigue; (2) achieve an agreement on accurate, reliable and responsive outcome measures of fatigue; (3) perform good quality RCTs.