Topiramate (McN 4853) lithium is a broad-spectrum antiepileptic agent. Topiramate lithium is a GluR5 receptor antagonist. Topiramate produces its antiepileptic effects through enhancement of GABAergic activity, inhibition of kainate/AMPA receptors, inhibition of voltage-sensitive sodium and calcium channels , increases in potassium conductance, and inhibition of carbonic anhydrase.