Levetiracetam in refractory epilepsy: a prospective observational study.

This prospective open-label study used flexible dosing schedules of levetiracetam (LEV) in patients with refractory epilepsy attending a single centre to explore its effectiveness in everyday clinical practice. One hundred and fifty-six patients with uncontrolled localisation-related or idiopathic-generalised epilepsy were prescribed adjunctive LEV following a 3-month baseline. The primary end points were seizure freedom for at least 6 months, > or = 50% reduction (responder) or <50% reduction for 6 months, or discontinuation of LEV due to lack of efficacy, adverse effects or both. Overall, 40 (26%) patients became seizure free on adjunctive LEV, including 8 (40%) with idiopathic-generalised epilepsy. Twenty-five (63%) of the seizure-free patients took 1000 mg LEV per day or less. A further 33 (21%) patients were classified as responders. LEV was withdrawn in 46 (29%) patients (27 adverse effects, 8 lack of efficacy, 11 both). Intolerable sedation, reported by 20 (13%) patients, was the commonest complaint leading to treatment failure. Behavioural side effects led to LEV withdrawal in 7 (5%) patients. LEV is an effective adjunctive treatment for refractory idiopathic and localisation-related epilepsies. Many patients who responded optimally to LEV did so at 1000 mg per day or less.