Research Area: Post-traumatic stress disorder, Alcoholism Biological Activity: Topiramate is an anticonvulsant drug. The exact mechanism of action is unknown, but four properties that may contribute to topiramate’s antiepileptic and antimigraine efficacy include a blockage of voltage-dependent sodium channels, an augmentation of gamma- aminobutyrate acid activity at some subtypes of the GABA- A receptors, antagonism of AMPA/kainate subtype of the glutamate receptor, and inhibition of the carbonic anhydrase enzyme, particularly isozymes II and IV . [1]