New antiepileptic agents: structure-activity relationships

Epilepsy is a common neurological condition, affecting 0.5 to 1% of the population worldwide. The chemical diversity and various mechanisms of action of anticonvulsants make it difficult to find a common way of identifying new drugs. Novel anticonvulsant agents are discovered through conventional screening and/or structure modification. Rational drug design process of a new anticonvulsant could be achieved in several ways. The first strategy is the identification of new targets through better understanding of molecular mechanisms of epilepsy. Another way is to modify already existing drugs and formulations. The new AEDs and anticonvulsant agents representing various structures have been reviewed in the present review. The newer agents include sulfonamides, amino acids, amides (analogs of g-vinyl GABA, N-benzylamides, 2,6-dimethylanilides, carboxyamides, hydroxyamides, alkanoamides); heterocyclic agents ((arylalkyl) imidazoles, tricyclic indoles, indazoles, arylpiperazine and piperazines, pyrrolidin-2,5-diones, pyridazinone, lactams, semi-thiosemicarbazones, thiadiazoles, quinazolin-4(3H)-ones, 2,5-disubstituted 1,2,4-thiadiazoles, xanthones, derivatives of isatin), enaminones, imidooxy compounds, and valproic acid derivatives. These new structural classes of compounds can prove useful for the design of future targets and development of new drugs.