The effectiveness of amantadine and dalfampridine in improving fatigue in patients with multiple sclerosis: A randomized, double-blind, clinical trial.

Background: Fatigue is a common complication associated with multiple sclerosis (MS). The aim of this study was to evaluate the impact of dalfampridine and amantadine on fatigue in patients with MS. Methods: This was a randomized, double-blind, clinical trial on patients with MS. The recruited patients were adults (≥ 18 years old) diagnosed with MS; their Expanded Disability Status Scale (EDSS) was between 0.0 and 5.5, and their fatigue was confirmed by the Modified Fatigue Impact Scale (MFIS). They were randomly assigned to the amantadine (100 mg twice daily) and dalfampridine (10 mg twice daily) for eight weeks. The primary outcome was the improvement of fatigue score, and the secondary outcome was assessment of quality of life by the Short-Form Health Survey (SF-36) and any reported side effects. Results: A total of 69 patients were recruited, and 54 of them were analyzed. The mean MFIS significantly improved in both groups after one and two months compared to baseline: amantadine: first month: 40.63 ± 14.35 (P = 0.040), second month: 36.56 ± 17.12 (P = 0.010); dalfampridine: first month: 38.29 ± 15.23 (P = 0.001), second month: 34.26 ± 18.30 (P = 0.001). However, the amount of changes from baseline was not significantly different (amantadine, P = 0.090; dalfampridine, P = 0.130). The amount of changes in quality of life showed no significant improvement (P = 0.210). Conclusion: The results showed that dalfampridine was not different with amantadine in improving fatigue in patients with MS; besides, it showed an acceptable safety profile. Therefore, it can be considered as a possible beneficial therapeutic agent in MS fatigue.