Prospective audit with adjunctive perampanel: preliminary observations in focal epilepsy

Purpose Perampanel (PER) was first licensed in the United Kingdom in 2012 for the adjunctive treatment of focal seizures with or without secondary generalization in adults and children over 12 years of age. It has recently also been approved for use as add-on therapy for patients with primary generalized tonic–clonic seizures. This prospective audit reports preliminary outcomes with adjunctive PER in patients with focal-onset seizures in everyday clinical practice using a standard design. Methods To date, 54 patients (38 males, 16 females; 21–65 years, median: 48 years) have completed the study. The median monthly seizure frequency was 4 (range: 1–60). At baseline, patients were taking a median of 2 other antiepileptic drugs (range: 1–4 drugs), with their seizures having previously failed to improve on a median of 3 schedules (range: 1–15 schedules). After 12 weeks of stable dosing, PER was added, aiming at a target range of 6–12 mg/daily. Review took place every 6–8 weeks until one of 4 endpoints was reached: seizure freedom for ≥ 6 months on a given PER dose, ≥ 50% (responder) or < 50% (marginal effect) seizure reduction over 6 months, compared with the prospective baseline, on the highest tolerated PER dose, or withdrawal of PER due to a lack of efficacy or side effects. Results Three (5.6%) patients have remained seizure-free, with 8 (14.8%) demonstrating a ≥ 50% response and a further 17 (31.5%) reporting a marginal effect. Of the 26 (48.1%) dropping out of PER treatment, 21 (38.9%) did so because of side effects. The commonest problems were nausea, vomiting, ataxia, dizziness, and sedation. Overall, 6 (11%) patients developed neuropsychiatric problems, with 3 reporting irritability and/or aggression. Two patients had substantial weight gain, and another patient suffered recurrent falls. Treatment with enzyme-inducing AEDs had no effect on PER dosing in patients responding to PER or withdrawing due to side effects. Significance These data support the value of adjunctive PER in some patients with pharmacoresistant epilepsy in everyday clinical practice