The Antiepileptic Effect of Riluzole and In Combination with Phenytoin on Maximal Electroshock Induced Seizures In Albino Rats: An Experimental Study

Abstract

Despite the introduction of several new therapeutic options, a significant fraction of the patients with epilepsy continue to live with uncontrolled seizures. Although large no. of antiepileptic drugs are available in the market, most of these agents have a limited spectrum of antiepileptic activity and all have certain negative properties that limit their utility and complicate patients management, so there is still a need for an ideal antiepileptic agent with properties like broad spectrum activity, rapid onset of action, least side effects, good oral bioavailability and low cost. Methodology: Albino rats weighing 150-200g, 6-8weeks old of either sex were used in the study. Rats were randomly allocated in to 9 groups; each group consists of six. Group 1: Control, I, II: Riluzole 5, 10mg/kg respectively, IV, V, VI: Phenytoin 25, 50, 100 mg/kg respectively, VII, VIII, IX: Riluzole 10 mg/kg in combination with phenytoin 25, 50, 100 mg/Kg respectively. Drugs were administered to all groups, orally by orogastric tube, as per the study subgroups. 30 minutes later, the rats were subjected to an electric shock by using an electro convulsiometer: Presence or absence of hind limb extensor, duration of clonus in sec. Result: Riluzole at both dosages of 5 & 10 mg/Kg did not modify the MES induced convulsions. Phenytoin at a dose of 25 mg/Kg & 50 mg/Kg could not abolish the hind limb extension. However, phenytoin at 100 mg/Kg produced 100% abolition of Hind limb extension. Phenytoin at 25 mg/Kg & 50 mg/Kg dosage insignificantly reduced the duration of Hind Limb Extensions without any effect on clonic phase. At the same time phenytoin at 100 mg/Kg significantly increased the duration of clonus from 9.8 to 18.3 seconds, but interestingly when Riluzole 10 mg/Kg was continued with Phenytoin 50 mg/Kg, the Hind Limb Extension was abolished in 50% animals. When the dose of Phenytoin was further increased to 100mg, it produced 100% protection by abolishing Hind Limb Extension. Similar effects were produced when Riluzole was combined with 100mg of Phenytoin. Conclusion: Riluzole alone was found to be ineffective against MES induced seizures, however it was found to enhance the antiepileptic effect of phenytoin against MES induced seizures.

Keywords : Maximal electroshock seizure, Riluzole, Phenytoin, Hind limb tonic extensor

Authors: Dr. Amol Jadhav, Mr. Vijayaprasad M. Sangishetti, Dr. Bana B. Nayak, Dr. Kiran P. Vakade, Mr. Vijaykumar N. Abhavathi
VIMS Health Sci Journal: 2016; 3 (2):50-52 | pdf PDF Full Article