Evaluation of isolated and combined effects of riluzole and sodium valproate in genetic absence epilepsy rats

Objective: In epilepsy treatment, drugs that increase GABAergic and decrease glutamatergic activity, like sodium valproate, are used. Riluzole is a neuroprotective drug that blocks glutamatergic neurotransmission and is a potential drug with its anti-seizure effects. This study evaluates the anti-seizure effects of sodium valproate and riluzole on the genetic absence epilepsy rat from Strasbourg (GAERS) model individually and combined. Materials and Methods: Adult male GAERS rats (n = 22) were used. Rats were administered 5/10 mg/kg riluzole, 150/300 mg/kg sodium valproate, 95% ethanol, and 5 mg/kg riluzole combinations with 150-300 mg/kg sodium valproate intraperitoneally. EEG recordings and locomotor activity tests were conducted. Statistical analysis was performed using GraphPad Prism. Results: Post-injection of 10 mg/kg riluzole significantly decreased the number of spike-wave-discharges (SWDs) (p = 0.04) compared to the control group. A synergistic effect was observed with 5 mg/kg riluzole and 150 mg/kg sodium valproate, reducing total seizure time (p = 0.03) and SWDs (p = 0.03). Conclusion: The study demonstrated the anti-seizure effects of 150/300 mg/kg sodium valproate, 10 mg/kg riluzole, and ethanol. A synergistic effect of 5 mg/kg riluzole with 150 mg/kg sodium valproate was noted. As an isolated or combined solution, riluzole shows potential, especially in resistant epilepsy treatment.