Effect of Amlodipine on the Antiepileptic Action of Lamotrigine, Gabapentin, Topiramate & Carbamazepine on Pentylenetetrazole and Maximal Electroshock Induced Seizures in Rats

Introduction: The trials for epilepsy treatment have increased with the introduction of newer antiepileptics like lamotrigine, gabapentin, topiramate.Calcium ion has important role in pathophysiology of epilepsy.Aim of the present study was to assess the effects of calcium channel antagonist amlodipine on the antiepileptic action of lamotrigine, gabapentin, topiramate, carbamazepine on pentylenetetrazole(PTZ) and Maximal electro shock seizure (MES) models in rats.Material and methods: Two hundred forty adult healthy wistar albino rats divided into 40 groups in 6 each.Half of the groups were alloted for each of both PTZ and MES model.Control (normal saline) and different doses of amlodipine (0.25, 0.5, 1 mg/kg)were administered intraperitoneally.Lamotrigine (18mg/kg), gabapentin (60mg/kg), topiramate (36mg/kg), carbamazepine (72mg/kg) were administered separately.Different doses of amlodipine was combined with lamotrigine (18mg/kg), gabapentin (60 mg/kg), topiramate (36 mg/kg), carbamazepine (72mg/kg).In PTZ model we observed for onset, duration and number of seizure.In MES model the onset and duration of tonic hind limb extension (THLE) was measured.Results: Amlodipine at moderate and high doses produced significant anticonvulsant effect and increased the anticonvulsant action of lamotrigine, gabapentin, topiramate and carbamazepine in a dose dependent manner in both PTZ and MES seizure models.Conclusion: The potential effect of amlodipine on various antiepileptic drugs is due to its action over various channels and neurotransmitter released.The results of this study deserve more attention as it can be a favourable treatment modality in patients of epilepsy with hypertension.