Efficacy and side effect of perampanel for refractory epilepsy

Abstract

Perampanel (PER) is a novel class of anti-epileptic drug and a noncompetitive inhibitor of the AMPA receptor. Some reports have described the efficacy and side-effects of PER in Japan. We prescribed PER to 33 refractory epilepsy patients, including some with intellectual disabilities and/or an age under 12 years. A "Good response" was defined as more than 50% seizure reduction, and we investigated the responder rates for focal seizure (Fs) and generalized tonic clonic seizure (GTCS). The effective rate for Fs and GTCS were both 50%, and the overall seizure rate was 52%. The efficacy in patients <12 years of age was similar to those > 12 years of age. Although there were no significant differences in the responder rates among the concomitant antiepileptic drugs (AEDs), two patients who received KBr combination treatment showed a good response. The responder rates with CYP3A4-inducing AEDs such as CBZ and PHT tended to be low (30% and 18%, respectively). Adverse events occurred in 55% of patients, including emotional and behavioral abnormalities in 30%, somnolence in 18%, and dizziness in 15%. We should therefore closely monitor young patients and those with intellectual disabilities, as emotional and behavioral abnormalities tend to occur with the administration of PER.