An antiepileptic that binds to SV2A (IC50s = 63.1, 79.4, and 126 nM, respectively) in human and cortex membrane preparations and in SV2A-expressing CHO cells; inhibits voltage-dependent sodium currents in primary rat neocortical neurons (IC50 = 41 μM), but does not inhibit GABA-, NMDA-, AMPA-, glycine-, or kainate-induced currents in primary mouse hippocampal neurons; inhibits convulsions in sound-sensitive and chemically- and maximal electroshock-induced seizures in mice (ED50s = 2.4, 30, and 113 mg/kg, i.p., respectively)