This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Pharmacology
Which of the following is not an antiepileptic agent? 
Select and explain. 
A. Phenytoin, B. Flunarizine, C. Topiramate, D. Carbamazepine
B: Flunarizine
Answer: B: Flunarizine 
Explanation: Ans. is 'b' i.e., Flunarazine o Phenytoin, Topiramate and carbamezepine are antiepileptics,o Flunarizine is a Ca+2 channel blocker used for the prophylaxis of migraine.Mechanism of action of different antiepiiepticsProlongation of Na+ channel inactivationo Phenytoino Carbamazepineo Valproateo Lamotrigineo Topiramateo ZonisamideFacilitation of GABA mediated Cl- channel openingo Barbiturateso Benzodiazepineo Vigabatrino Valproateo Gabapentino TiagabineInhibition of T type Ca++ currento Ethosuximideo Trimethadioneo ValproateDecrease of excitatory neurotransmissiono Felbamale (Katzung 10th/e 382)