Abstracts

Rationale: For patients with refractory epilepsy, newer epilepsy medications offer the chance for seizure improvement. Perampanel (PER), with its novel mechanism of non-competitive AMPA receptor antagonist, has shown efficacy for both focal and primary generalized tonic-clonic seizures as adjunctive treatment. Two main considerations in selecting AEDs are their efficacy and tolerability, which are probably best evaluated by retention rate, defined as the percentage of patients remaining on the medication after a specified time period. We reviewed retention rate of PER where PER dosage was increased according to current US prescribing standards. Methods: Patients with a current diagnosis of partial onset or primary generalized epilepsies who had been prescribed PER as adjunctive treatment for the past two years were retrospectively reviewed to assess retention rate and reasons for discontinuation of PER. Existing medical records were reviewed in order to obtain information regarding age, sex, type of epilepsy, length of PER treatment and reasons for discontinuation. Retention rate was calculated based off of the total number of patients remaining on PER therapy at the time of chart review. Results: A total of 38 patients were identified for the purpose of the study. Patients were aged 20 to 77 years old (median age was 34.5) and 52.6% were female. Epilepsy diagnoses included Partial Onset Epilepsy (20), Lennox-Gastaut Syndrome (6), Idiopathic Generalized Epilepsy (8) and Juvenile Myoclonic Epilepsy (4). PER was initiated as an adjunctive therapy in all 38 patients. PER was titrated in 2 mg increments every two weeks and in a few cases, 2 mg increments every week. Patients had an average PER dose of 5.3 mg/day with the median length of PER treatment at 92 days. Of the 38 patients who initiated PER, 18 reported AEs including behavioral (aggression, irritability, anger, mood swings, agitation and easily frustrated), ataxia with associated falls, dizziness and nausea. All patients with reported AEs discontinued PER except for 1 whose dose was decreased to improve tolerability. The median length of time to PER discontinuation was 42 days. At the time of chart review, retention rate was calculated to be 47.4%. Conclusions: Our study shows the retention rate of PER falls within the lower end of the previously published data (44-89%: Trinka et al, 2016). The main reasons for discontinuation of PER were primarily due to a lack of tolerability. Albeit small sample number in our study, retention rate did not differ significantly when PER was titrated at the recommended titration rate of 2 mg increments every two weeks.References:Trinka E, Steinhoff BJ, Nikanorova M, and Brodie MJ. Perampanel for focal epilepsy: insights from early clinical experience. Acta Neurologica Scandinavica. 2016 Mar; 133(3): 160-172. Funding: None