ANTIEPILEPTIC EFFECTS OF TOPIRAMATE ON AMYGDALOID KINDLING IN RATS

We examined the antiepileptic properties of topiramate (TPM) in amygda loid (AM) kindling in rats. Electrodes were implanted into the left AM of adult male Wistar rats. The animals were kindled at the after-disc harge (AD) threshold. After the completion of kindling, the generalize d seizure triggering threshold was determined. The drugs were administ ered intraperitoneally in animals which showed stable generalized conv ulsions at near-threshold stimulation. Intraperitoneal administration of TPM at doses of 25 mg/kg or more produced an anticonvulsive effect, but did not readily suppress limbic seizures. Complete suppression of AD was observed in only 3/8 rats at the highest dose of 200 mg/kg, wh ich was not statistically significant. On the other hand, TPM at 100 a nd 200 mg/kg significantly delayed AM kindling. Thus, TPM showed modes t therapeutic properties of conventional antiepileptic drugs in kindli ng model, those of TPM more closely resemble those of phenobarbital an d the benzodiazepines than those of phenytoin and carbamazepine. (C) 1 998 Elsevier Science B.V. All rights reserved.