Calcium channel blockers verapamil and nimodipine inhibit kindling in adult and immature rats.

The calcium channel blockers verapamil (VPM) and nimodipine (NMD) were administered to adult or immature (16-day-old) rats to determine their effects on amygdala-kindled seizures. The afterdischarge threshold (ADT) kindling rate and degree of postictal refractoriness were determined for two doses of VPM (0.5 and 5.0 mg/kg in rat pups and 2 and 10 mg/kg in adult rats) or 30 mg/kg nimodipine (NMD). Neither VPM nor NMD affected the ADT of the amygdala in adult or immature rats. VPM retarded the rate of kindling in both adult and immature rats in a dose-dependent manner; the number of stimulations required to progress through seizure stages were increased. NMD 30 mg/kg reduced the kindling rate and AD duration in both adult and immature rats. Neither drug was able to suppress recurrent seizures elicited by repetitive stimulation. These results suggest that verapamil, and possibly NMD may be of clinical utility in treatment of epilepsy, especially complex partial seizures.