Anticonvulsants glutamate receptors

Topiramate [to PYRE a mate], a chemical relative of fructose, has several actions at therapeutic concentrations that contribute to its anticonvulsant activity. These actions include blockade of Na+-channels, increased GABA activity at GABA receptors, and blockade of some glutamate receptors. When added to conventional therapy in refractory patients, topiramate causes a 50 percent or greater reduction in the number of partial seizures in approximately 50 percent of the patients. 

APV (2-amino-5-phosphonopentanoic acid) is a competitive (NMDA) GLUTAMATE RECEPTOR ANTAGONIST which has anticonvulsant/antiepileptic actions. It is used as a pharmacological tool. 

A. Both dextromethorphan and its o-demethylated metabolite appear to antagonize /V-methyl-D-aspartate (NMDA) glutamate receptors, which may explain anticonvulsant properties and protection against hypoxia-ischemia observed in animal models. 

Synthesis of novel anticonvulsants as glutamate receptors antagonist... 

Myhrer, T., Enger, S., Aas, R, 2010b. Modulators of metabotropic glutamate receptors microinfused into perirhinal cortex anticonvulsant effects in rats challenged with soman. Eur. J. Pharmacol. 636, 82-87. 

Excitatory neurotransmitters also may be involved in the appearance of epilepsy, since the bursting activity typically seen during epileptic discharges may be due in part to the action of glutamate acting on A-methyl-o-aspartate (NMDA) receptor channels to produce depolarization. It is likely that a major part of the anticonvulsant activity of felbamate involves blockade of the NMDA receptor. Table 32.2 summarizes the most likely mechanism of action associated with available anticonvulsant drugs. 

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