The first clinical trials on which approval of levetiracetam was based, were conducted between 1995 and 2000. Levetiracetam has been investigated as add-on therapy for partial seizures in 3 placebo-controlled phase 3 studies. In these studies, 904 patients, in both the United States and Europe, had experienced refractory partial onset seizures with or without secondary generalization for at least 2 years and had taken 2 or more standard antiepileptic drugs. The measure of effectiveness included the responder rate (incidence of patients with a greater than 50% reduction from baseline in partial onset seizure frequency for the entire treatment period). The responder rate was statistically significantly greater in patients taking levetiracetam 1000 mg/day, 2000 mg/day, or 3000 mg/day as compared to placebo within each study. The responder rate was between 22.8% and 33% on 1000 mg, 31.6% on 2000 mg, and between 39.4% and 42.1% on 3000 mg, as compared to placebo rates of 10.9% to 16.7% (13). A few selected clinical trials of levetiracetam during the previous decade are cited in this article.
A randomized, single-blind, placebo-controlled study showed that levetiracetam administered by intravenous infusion was well tolerated in healthy subjects and the pharmacokinetic profile was consistent with orally administered levetiracetam.
In a prospective add-on study of children with refractory epilepsy, levetiracetam was effective in 54.3% of patients, decreasing seizure frequency to at least 50% of baseline frequency (34).
In Asia SKATE II study, levetiracetam was well tolerated and efficacious as adjunctive therapy for partial epilepsy in Asian populations (16).
A Cochrane review of 11 clinical trials concluded that it is reasonable to continue the use of levetiracetam in both adults and children with drug-resistant focal epilepsy, but longer-term effects of monotherapy on generalized seizures cannot be determined from these results (22).
An open phase II trial of levetiracetam following acute head injury in children who were at risk for developing posttraumatic epilepsy showed that only 1 child among 40 participants developed this complication (24). These results support the conduct of a prospective phase II levetiracetam trial following acute head injury in children at risk for posttraumatic epilepsy.
A metaanalysis of randomized-controlled trials of levetiracetam as an adjunctive therapy in epilepsy of multiple seizure types showed efficacy in reducing the frequency of seizures in partial as well as idiopathic generalized epilepsy in both adults and children, with good tolerance (09).
A randomized, double-blind, placebo-controlled crossover study of the effects of levetiracetam on cognition, mood, and balance in healthy older adults showed that the drug was well tolerated in this population and had pharmacokinetic advantages (28).