Abstract:
Background: The currently available antiepileptic drugs have a low therapeutic index,
and provide satisfactory seizure control in only 60-70% of patients. Calcium channel
blocker has shown potentials of a useful add-on drug for the existing antiepileptic drugs.
Materials and Methods: Antiepileptic potential of calcium channel blockers (nifedipine
and verapamil) was evaluated in MES and PTZ models of epilepsy in comparison and
combination with phenytoin (25 mg/kg) and sodium valproate (250 mg/kg) in albino
wistar rats; half the dose was used when calcium channel blockers (nifedipine and
verapamil) was combined with either phenytoin or sodium valproate. The time taken
before the onset of clonic convulsions (latency), the duration of clonic convulsions, the
percentage of seizure protection and percentage mortality were recorded.
Results: Calcium channel blockers (nifedipine and verapamil) were found to reduce the
durations of tonic extensor phase, duration of convulsion in a statistically significant way
in the both MES and PTZ model; and while used in combination with phenytoin and/or
sodium valproate, the results were statistically significant than both the drugs given
individually. In both these group statistically significant increased percentage epilepsy
protection and decrease in percentage mortality was noted when compared to control
groups (p < 0.05).
Conclusion: Calcium channel blockers (nifedipine and verapamil) have shown potency
as an individual antiepileptic drug as well as a useful add-on therapy with standard
antiepileptic drugs like phenytoin and sodium valproate in both the models of epilepsy.
