Additive interaction of levetiracetam with lamotrigine in the mouse 6 Hz psychomotor seizure model – an isobolographic analysis

Abstract

The aim of this study was to characterize the anticonvulsant effects of levetiracetam (LEV) in combination with lamotrigine (LTG – a second-generation antiepileptic drug), in the mouse 6 Hz psychomotor seizure model. Limbic (psychomotor) seizure activity was evoked in albino Swiss mice by a current (32 mA, 6 Hz, 3 s stimulus duration) delivered via ocular electrodes and isobolographic analysis for parallel dose-response relationship curves (DRRCs) was used to characterize the consequent anticonvulsant interactions between the drug combinations. Results indicated that LEV administered singly was associated with a DRRC that was parallel to that for LTG. With isobolography for parallel DRRCs, the combination of LEV with LTG at three fixed-ratios of 1:3, 1:1 and 3:1 exerted additive interaction. LEV combined with LTG exerted additive interaction in the mouse 6 Hz psychomotor seizure model.