Many people with MS find that difficulty walking is one of the most challenging parts of their MS, and that it restricts their daily activities significantly. Dalfampridine, a potassium channel blocker, formerly known as fampridine SR (sustained release), has been shown to improve impulse conduction in nerve fibers in which the myelin has been damaged. Although dalfampridine is not a disease modifying therapy (DMT), this agent offers a novel approach to target MS symptoms, specifically walking ability.

Investigators at ECTRIMS (European Committee for Treatment & Research in Multiple Sclerosis) reported that after an average of almost 2 years of taking dalfampridine, one quarter of the 269 study participants had an average improvement in walking speed of 22%. This was in contrast to an 8% decline in speed among those who did not respond to treatment.

Following completion of the two phase III clinical trials, improvement was reported in 35% to 43% of those who received treatment. People whose walking speed increased with treatment were also found to have a significant improvement in leg strength. In February 2010, the U.S. Food and Drug Administration approved the marketing of dalfampridine (Ampyra™) for its ability to improve walking in people with any type of multiple sclerosis. Currently, dalfampridine is not approved, or available in Canada for this indication.