One-Year Retention Study of Adjunctive Perampanel Treatment in Epilepsy Patients

Objectives Perampanel is a recently introduced antiepileptic drug (AED) with a unique action mechanism of noncompetitive and selective -amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid antagonist. Because of delayed approval of perampanel in most Asian countries, there is limited information on the clinical usefulness of perampanel in the Asian population. We performed a retrospective analysis of retention rate, seizure outcome, and adverse events for perampanel treatment in South Korea. Methods This was a retrospective, single-center, 1-year observational study. A total of 137 epilepsy patients (86 men, 51 women; age, 17-86 years) who were treated with perampanel as an adjunctive treatment were included. Perampanel was administered at a starting dose of 2 mg/d, and optimal-dose adjustments were made according to individual clinical responses. Efficacy and tolerability were analyzed during a 1-year follow-up. Results The overall retention rate was 71.3% at the 6-month follow-up and 61.0% at the 1-year follow-up. Retention rates were similar between patients with 1 concomitant AED and those taking 2 or more concomitant AEDs. The most common adverse event was somnolence, followed by dullness and psychiatric reactions, and the presence of psychiatric comorbidity was significantly associated with the development of psychiatric adverse reactions. Conclusions We showed that the retention rate and adverse events for adjunctive perampanel treatment in the Korean population were comparable with those in Western countries. Our study also suggests that adjuvant perampanel treatment may be effective in patients taking a higher number of concomitant AEDs and that psychiatric comorbidity may be a risk factor for perampanel-induced psychiatric reactions.