DOUBLE-BLIND, PLACEBO-CONTROLLED, CROSSOVER STUDY OF LAMOTRIGINE IN TREATMENT-RESISTANT PARTIAL SEIZURES

The results of a multicentre, randomised, double-blind, placebo contro lled, crossover trial of lamotrigine as add-on therapy in patients wit h partial seizures poorly controlled by established antiepileptic drug s (AEDs) are presented. The study consisted of two 12 week treatment p eriods each followed by a four week washout period. During the lamotri gine treatment phase, patients received 150 mg or 300 mg daily dose de pending on their concomitant AEDs to achieve concentrations in the ran ge 1-3 mg/L. Forty one patients were entered at four centres and all p atients entered completed the study. There was a highly significant (p < 0.001) decrease in total seizure counts on lamotrigine compared wit h placebo. Overall, 22% of patients experienced at least a 50% reducti on in the total numbers of all seizure types on lamotrigine, compared with none on placebo. When the total numbers of partial seizures (simp le and complex partial) were analysed there was also a significant (p < 0.05) reduction in seizure counts on lamotrigine compared with place bo. When total numbers of secondarily generalised seizures were compar ed the trend for a reduction in this seizure type did not achieve sign ificance (0.05 < p < 0.1). Concomitant AED plasma concentrations were virtually unchanged. It is concluded that lamotrigine is an effective AED in the treatment of therapy-resistant partial seizures.