<prompt> All of the following antiepileptic agents act Na channel except -VigabatrinPhenytoinValproateLamotrigine  <response>: Ans. is a i.e., Vigabatrin Mechanism of action of different antiepileptics. Prolongation of Na channel inactivation Facilitation of GABA mediated Cl- channel opening Inhibition of T type Ca current Decrease of excitatory neurotransmission o Phenytoin o Carbamazepine o Valproate o Lamotrigine o Topiramate o Zonisamide o Barbiturates o Benzodiazepine o Vigabatrin o Valproate o Gabapentin o Tiagabine o Ethosuximide o Trimethadione o Valproate o Felbamale 