A retrospective, observational study of perampanel in refractory and super-refractory status epilepticus

The outcomes of administration of Perampanel (PER) which is a β-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl)propionic acid (AMPA) receptor antagonist for the treatment of refractory status epilepticus (RSE) and Super-refractory (SRSE) were previously reported in small cohort studies and case reports. We report efficacy and side effect results of an observational cohort of 75 patients treated with PER for RSE and SRSE.

This was a single-center, retrospective, observational study of patients with RSE admitted to the neurocritical care unit between April 2017 and September 2019 who received treatment with PER. The primary outcome was the occurrence of a definite response to PER, which was defined as clear resolution of the ictal pattern and/or seizures within 72 h of delivery of PER which was the last administered antiseizure medication (ASM). Secondary outcomes included the percentage of patients other response types (partial responder or non-responder), as well as the rate of adverse effects.

A total 75 patients were included in our analysis. PER was initiated as the median sixth ASM at a median initial dose of 12 mg. For the primary outcome, 31 (41.3%; 95% confidence interval 31.0%-53.0%) patients were classified as a definite responder. Seven patients (9.3%) experienced an adverse effect that was attributed to PER, with the most common being sedation in four patients.

In our retrospective cohort of RSE, we observed a definite response rate of 41.3% within 72 h of PER initiation. PER was well tolerated with few documented adverse effects. Further prospective studies are needed to confirm the role of PER in treating patients with RSE.