Dose-response effect of levetiracetam 1000 and 2000 mg/day in partial epilepsy.
OBJECTIVE
To evaluate the efficacy, dose-response, tolerability, and withdrawal effects of levetiracetam (Keppra) as adjunctive therapy in adult patients with partial epilepsy.


METHODS
In this European multicenter, double-blind, randomized, cross-over trial, levetiracetam 1000 or 2000 mg/day given in two divided doses was compared to placebo as add-on therapy in 324 patients with refractory partial seizures with or without secondary generalization. This trial consisted of six periods: an 8- or 12-week baseline, a treatment period A (4-week titration and 12-week evaluation), a treatment period B (4-week titration and 12-week evaluation), and a withdrawal period. During each evaluation period (A and B), patients received two of the three possible treatment regimens.


RESULTS
This study provides additional information on dose-response effects and withdrawal phenomena and confirms the responder and seizure freedom rates previously reported in the parallel part of the study (Epilepsia 41 (2000) 1179-1186). Both doses of levetiracetam significantly decreased mean partial seizure frequency compared with placebo (P<0.001), and significantly more patients receiving levetiracetam had > or = 50 and > or = 75% reductions in partial seizure frequency (1000 mg, P=0.004 and P=0.043, respectively; 2000 mg P=0.001 and P<0.001, respectively). In addition, 5.5% (10/183) of patients receiving levetiracetam 1000 mg/day and 6.3% (11/175) of patients receiving levetiracetam 2000 mg/day were seizure-free during the corresponding evaluation period, compared with 1.2% (2/172) of patients on placebo. A within-patient comparison revealed a significantly greater responder rate for the higher levetiracetam dose (P=0.018). The most commonly reported adverse effects (> or = 5% and more frequent in one of the groups with levetiracetam) were headache, asthenia, infection, somnolence, pharyngitis, dizziness, and pain. No withdrawal-related adverse events were reported during the cross-titration period.


CONCLUSIONS
Levetiracetam was effective and well-tolerated and decreased seizure frequency in a dose-dependent manner, with no evidence of typical withdrawal-related adverse events or rebound phenomena after withdrawal or down-titration.
Boon
P
P
Department of Neurology, University Hospital Ghent, De Pintelaan 185, B-9000 Gent, Belgium. paul.boon@rug.ac.be
Chauvel
P
P
Pohlmann-Eden
B
B
Otoul
C
C
Wroe
S
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000927:Anticonvulsants / Q000008:administration & dosage* / Q000009:adverse effects; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004828:Epilepsies, Partial / Q000188:drug therapy*; D005260:Female; D006801:Humans; D000077287:Levetiracetam; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010889:Piracetam / Q000008:administration & dosage* / Q000009:adverse effects / Q000031:analogs & derivatives*
D000927:Anticonvulsants; D000077287:Levetiracetam; D010889:Piracetam