Retention Rate and Efficacy of Perampanel with a Slow Titration Schedule in Adults

The manufacturer of perampanel (PER) suggests an initial adult dose of 2-4 mg/day and an upward dose titration of 2 mg at no more frequently than 1- or 2-week intervals when used with enzyme-enhancing antiepileptic drugs (AEDs) or nonenzyme-enhancing AEDs, respectively. The general practice in our clinic is an initial dose of PER 2 mg/day and titrated by 2 mg/4 weeks to an initial target of 6 mg/day. Retrospective chart audit of patients starting PER in an adult epilepsy clinic between September 2013 and November 2016 with at least one 6-month follow-up visit was reviewed. Data collection included patient demographics, seizure characteristics, past and concurrent therapy, monthly seizure frequency before PER and at 6-month visit, and characteristics of PER discontinuation. Efficacy of treatment was assessed with the Engel classification and 50% responder rate. N = 102 patients; mean age = 40 years and 54% females. Focal onset seizures 85%, generalized 13%, and unknown 2%. Median prior AED exposure = 6 (range 3-20); median concomitant AED use = 2 (range 1-5). Follow-up range was 6-37 months. The median seizure frequency/month prePER treatment was 6 (range 0-30) for focal onset seizures and 1 (range 0-6) for generalized seizures. The retention rate amongst all patients at 6 months was 78.4%. At 6-month follow-up, 36% of all patients achieved Engel class I (seizure freedom) (30.7% of patients with focal onset seizures and 63.6% with generalized epilepsy). The 50% responder rate was 52% and 82% for focal and generalized epilepsy, respectively. PER has a good retention rate when titrated slowly and thus encouraging seizure freedom results in an otherwise medically refractory epilepsy population.