To assess the comparative efficacy and tolerability of add-on therapy versus alternative monotherapy in epileptic patients with partial seizures refractory to initial treatment or sequential monotherapies.
To determine the optimal therapeutic strategy in epileptic patients with epilepsy refractory to initial treatment or sequential monotherapies, 440 patients with partial non-idiopathic epilepsy who had failed to achieve freedom from seizures despite treatment with a single drug will be randomized to two groups. One group will be crossed-over to an alternative drug having a different mechanism of action (for example, carbamazepine or vigabatrin in patients who had failed on valproic acid monotherapy and valproic acid or vigabatrin in patients who had failed on carbamazepine monotherapy) while in the other group the alternative drug will be added on. In both groups drug dosage will be individualized based on clinical response and serum drug level determinations. Seizure frequency and the occurrence of adverse events will be assessed over a 1-year follow-up period to assess potential differences between the two groups. The primary outcome parameter will be represented by retention time on the allocated treatment policy. Other outcome parameters will include: dissatisfaction time with the allocated treatment policy, time to first seizure after achieving target dosage, proportion of patients achieving at least a 50% reduction in seizure frequency during the last 3 months of follow-up, proportion of patients becoming seizure free and achieving 6-month remission, seizure number at different study periods compared with seizure number at baseline, number of treatment failures, proportion of patients with adverse events.