Abstracts

Rationale: Perampanel (PER) is a noncompetitive AMPA glutamate receptor antagonist used in the treatment of focal and primary generalized tonic-clonic seizures. The objective of this study is to gauge the tolerability of PER, with special attention to neuropsychiatric side effects. Methods: We performed a retrospective chart review of 33 patients treated with PER for epilepsy of difficult control to assess the incidence of side-effects. Nine of the patients were < 17 years of age with a range of 5 to 60 years. Results: 26 patients (78.8%) reported at least one adverse effect (AE). Irritability/aggressiveness/anger (IAA) was noted in 17 patients (51.5%), dizziness/ataxia in 7 (21.2%), sedation in 6 (18.2%), mood changes/depression in 3 (9.1%), and psychosis/hallucinations in 2 (6.1%). PER was discontinued in 21 patients (63.6%), with lack of efficacy as the sole reason for discontinuation in only 3, and pregnancy in 1. Of the 17 patients with IAA, 13 discontinued the medication, with only 1 solely due to lack of efficacy. Dose of PER at which IAA was first reported is as follows: 2 mg/d: none; 3 mg/d: 3 (17.6%); 4 mg/d: 8 (47.1%); 6 mg/d: 4 (23.5%); 8 mg/d: 2 (11.8%). Among the 17 patients with IAA in response to PER, 10 (58.8%) had reported a similar adverse response to levetiracetam (LEV). Conclusions: Neuropsychiatric/behavioral side effects appear to be the most common limiting factor with the use of PER, observed in roughly half of our patient population. These side effects tend to appear at low doses, with a peak of emergence at 4 mg/d. A history of neuropsychiatric adverse effects with LEV appears to be a risk factor for developing similar adverse effects with PER.