Level 3: Lacking direct evidence
Dalfampridine (Ampyra) extended release tablets, previously called Fampridine-SR, have been approved by the FDA to improve walking in patients with multiple sclerosis. In two clinical trials with 507 patients, the drug was associated with consistent improvement in walking speed on a 25-foot walk when compared with placebo (NNT 4). However, the clinical relevance of this outcome is unclear (Lancet. 2009;373: 732-738, Neurology. 2008;71:1134-1141).