Prolonged-release (PR) fampridine (Fampyra®), a potassium channel blocker, is the first agent to be specifically indicated for the improvement of walking in patients with multiple sclerosis (MS). In clinical trials in patients with MS with impaired walking, PR fampridine 10 mg twice daily improved walking ability to a significantly greater extent than placebo, with improvements being maintained with long-term therapy. PR fampridine 10 mg twice daily is generally well tolerated.