Levetiracetam as add-on therapy for idiopathic generalized epilepsy syndromes with onset during adolescence: analysis of two randomized, double-blind, placebo-controlled studies.

PURPOSE: To assess the efficacy and tolerability of adjunctive levetiracetam in idiopathic generalized epilepsy (IGE) syndromes with onset during adolescence: juvenile absence epilepsy (JAE), juvenile myoclonic epilepsy (JME), and generalized tonic-clonic seizures on awakening (GTCSA).

METHODS: Supplementary analysis of two double-blind, placebo-controlled trials. Patients received levetiracetam (target dose: adults 3000 mg/day; children 60 mg/kg/day; n=15 JAE, 78 JME, and 22 GTCSA) or placebo (n=12 JAE, 89 JME, and 27 GTCSA) for 16-24 weeks (including 4-week uptitration) in addition to 1-2 antiepileptic drugs.

RESULTS: Responder rates (> or =50%) were significantly higher for levetiracetam versus placebo for JAE (53.3% vs. 25.0%; p=0.004), JME (61.0% vs. 24.7%; p<0.001), and GTCSA (61.9% vs. 29.6%; p=0.024). Seizure freedom rates were significantly higher for levetiracetam versus placebo for JME (20.8% vs. 3.4%; p=0.002); differences between treatment groups for JAE (33.3% vs. 8.3%; p=0.15) and GTCSA (23.8% vs. 11.1%; p=0.45) appeared to be clinically relevant, but did not reach statistical significance. The most frequent adverse events on levetiracetam were headache (levetiracetam 16.8% and placebo 14.8%) and somnolence (levetiracetam 9.7% and placebo 3.9%).

CONCLUSIONS: Adjunctive levetiracetam was well tolerated and provided effective seizure control over 16-24 weeks in patients with insufficiently controlled IGE syndromes with onset during adolescence (JAE, JME, and GTCSA), supporting levetiracetam's broad spectrum of efficacy.