Sustained-release fampridine in Multiple Sclerosis

Sustained-release fampridine, a slow release formulation of 4-aminopryridine, is a voltage-dependent potassium channel blocker licensed for the treatment of walking difficulties in multiple sclerosis (MS). Studies have demonstrated that approximately one-third of MS patients respond with a clear benefit to their walking speed. Sustained-release Fampridine is not currently available on the National Health Service (NHS), although it has been approved by the Food and Drug Administration (FDA) in the USA and European Medicine Agency (EMA). It appears to have an acceptable adverse event profile, with data from open-label extension studies now becoming available. Concerns have been raised that the use of fampridine may increase the risk of seizures, which were seen at higher rates in patients treated with high doses of sustained-release fampridine. The rate of seizures in those patients on lower doses has not been found to be significantly increased. There are significant barriers at present to the widespread use of fampridine in the UK, which have limited its use in clinical practice to date. Patients with MS are in need of interventions to improve walking and many clinicians feel that this drug may have a role in the symptomatic management of MS.