A sodium channel blocker (IC50 = 138 nM in a radioligand binding assay); inhibits sodium uptake in a dose-dependent manner in rat cortical synaptosomes; protective against MES-induced seizures in mice (ED50s = 4.7 and 6.3 mg/kg, for oral and i.p. administration respectively); high-dose administration (30 mg/kg) prevents picrotoxin-induced seizures; low-dose administration (10 mg/kg) reduces seizure number and duration