Comparison of seizure potentiating effect of first and second generation antihistamines

Aims: There are controversies regarding the proconvulsant effect of first and second generation antihistamines. To compare the seizure potentiating effect of first generation antihistamine cyroheptadine with second generation fexofenadine in animal models of epilepsy. Methods: Thirty rats were used. In bothMES and PTZ model, rats were divides into three groups(n=6). Group I to III received sodium alproate, sodium valproate + cyproheptadine and sodium valproate + fexofenadine respectively in both the models. In MES model 30 minutes after drug administration seizures were induced. Duration of seizures, recovery period and hindlimb extension were recorded. In PTZ model, PTZ was injected 30 minutes after drug administration. Latency and total duration of seizure was recorded. Results: In MES model, recovery period was significantly more in cyproheptadine + sodium valproate group as compared to sodium valproate alone. In PTZ model mortality was seen only in the combination groups. Conclusion: Though antihistamines have a seizure potential, second generation antihistamine, fexofenadine was superior to cyproheptadine in MES model of epilepsy.