ABSTRACT
This chapter discusses novel anticonvulsant drugs that are thought to act either by enhancing Gamma Aminobutyric Acid (GABA)-mediated inhibition or by diminishing excitatory neurotransmission mediated by glutamate or aspartate. Impairment of GABA-mediated inhibition can induce either focal or generalized seizures. This is seen with compounds blocking the synthesis of GABA and with compounds blocking its postsynaptic action. The proconvulsant action of various esters of ß-carboline 3-carboxylate was identified as a result of a search for endogenous agents acting on the benzodiazepine receptor. Glutamate is the principal fast excitatory neurotransmitter in the brain and is involved in epileptic activity in many different ways. The local initiation of the seizure activity may depend on hyperactivity or hypersensitivity within the glutamatergic system. Lamotrigine has been compared with placebo as addon therapy in three double-blind clinical trials in adult patients with drug-resistant epilepsy.
