Expanding Antiepileptic Drug Options: Clinical Efficacy of New Therapeutic Agents

Results of double-blind, placebo-controlled, add-on trials of topiramate (TPM), lamotrigine (LTG), and vigabatrin (VGB) in refractory partial epilepsy were reviewed. In three European multicenter studies of TPM, the clinical efficacy of 400-, 600-, and 800-mg/day target dosages was demonstrated. In a similarly designed United States trial, LTG was significantly superior to placebo at a 500-mg/day dosage but not at a 300-mg/day dosage. A meta-analysis of a number of smaller trials of VGB suggests that a > or = 50% reduction in seizures is observed in approximately 45% of patients with refractory partial epilepsy. All of these newer antiepileptic drugs have shown efficacy in well-controlled trials and should contribute significantly to our ability to manage partial epilepsy.