This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'All of the following antiepileptic agents act Na+ channel except - \nSelect and explain. \nA. Vigabatrin, B. Phenytoin, C. Valproate, D. Lamotrigine', 'role': 'user'}, {'content': "Answer: A \nExplanation: 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", 'role': 'assistant'}]