Dalfampridine in multiple sclerosis

Dalfampridine (4-aminopyridine or 4-AP) is a potassium channel blocker that is historically known in the literature as fampridine (INN). This review begins with an outline of the pharmacology and pharmacokinetics. Early clinical trials are highlighted, followed by a review of the more recent phase II and III placebo-controlled clinical trials that have examined dalfampridine in multiple sclerosis patients. In these trials, extended-release dalfampridine was shown to result in an average 25% increase in the walking speed in more than one-third of the patients who received the drug and met the prescribed criteria for consistent responders. The safety profile of dalfampridine is also reviewed, with a focus on the risk for epileptic seizures as an adverse effect.