Efficacy and tolerability of levetiracetam during 1-year follow-up in patients with refractory epilepsy

Problem: Levetiracetam (LEV) is a new antiepileptic drug shown to be effective for the treatment of partial seizures in pivotal clinical trials. We investigated the long-term efficacy and tolerability of LEV as add-on therapy, regardless of seizure type, especially in persons who would not be eligible for clinical trials due to factors such as mental retardation and concomitant psychiatric disorders. Methods: Ninety-eight patients participated and were followed for 1 year. Demographic data, seizure frequency, and side effects were recorded at baseline and during the 1-year follow-up. The first 35 patients were given LEV at a starting dose of 500 mg b.i.d. with weekly increments of 1000 mg (fast titration). The other patients were given LEV with a starting dose of 250 mg b.i.d. with weekly increments of 250 mg (slow titration). Results: Fourteen patients were completely seizure free after titration to effective dose and 57 were responders with >50% seizure reduction for the first year. In the group with generalized seizures, 1 out of 19 became seizure free, but 8 patients had >50% decrease. Average dose at 1 year was 1900 mg ( 900). Seventeen of 38 discontinuations were due to adverse effects and 21 were due to lack of efficacy. With fast titration, 15 out of 35 (43%) experienced tiredness during the first 12 weeks, and with slower titration 20 of 63 (32%) experienced tiredness. The difference was not statistically significant. Four out of the five patients who discontinued due to behavioral adverse events (mainly irritability) previously had behavioral problems and/or mental retardation. One patient discontinued due to psychosis. Conclusions: Levetiracetam appears to be well tolerated in patients with severe epilepsy and shows efficacy in a long-term follow-up. Behavioral adverse events were noted in a small number of patients and occurred mainly in patients who had a history of behavioral disturbance or were mentally retarded. These data from an open population are consistent with the findings of clinical trials. (C) 2002 BEA Trading Ltd. Published by Elsevier Science Ltd. All rights reserved.