Comparative effects of felbamate and other compounds on N-methyl-D-aspartic acid-induced convulsions and lethality in mice.

Felbamate and selected compounds were evaluated for their ability to protect against N-methyl-D-aspartic acid (NMDA)-induced convulsions and lethality in mice. Convulsions produced by intracerebroventricular administration of NMDA (0.8 micrograms per mouse) were antagonized by felbamate, phenytoin, carbamazepine, phenobarbital, valproate, diazepam, 2-amino-5-phosphonovalergic acid (APV), dextromethorphan and ketamine. NMDA (350 mg kg-1 intraperitoneally) produced 100% lethality in mice. Felbamate, phenytoin, and phenobarbital were ineffective in preventing NMDA-induced lethalities, whereas diazepam, APV, ketamine and dextromethorphan were the most potent compounds in preventing lethalities. Any relationship between the protective effects of felbamate against NMDA-induced seizures and competitive or non-competitive antagonism of NMDA receptor sites, however, cannot be established until further experimentation is carried out.