Efficacy and safety of perampanel in refractory and super-refractory status epilepticus: cohort study of 81 patients and literature review

Background: The effective dose of perampanel in status epilepticus (SE), refractory SE (RSE), and super-refractory SE (SRSE) in humans is unknown, and the potential of perampanel in treating SE has not been evaluated in a large cohort.

Methods: Data of intensive care patients with RSE and SRSE treated with perampanel were retrospectively reviewed and analyzed.

Results: Eighty-one patients received perampanel, including 39 females with median age 64 [17-91] years, perampanel responders (n = 27), and non-responders (n = 54). The initial perampanel dose was positively associated with treatment response in patients with RSE or SRSE (OR = 1.27, 95% CI 1.03-1.57, p = 0.025), while the maximum dose was negatively associated with treatment response (OR = 0.74, 95% CI 0.58-0.96, p = 0.022). Hypoxia caused seizures in six patients; five died in hospital and one had severe disability. A statistically non-significant tendency toward better response was found in patients with unique SE type and cause, particularly in nonconvulsive status epilepticus (NCSE) without coma (NCSE without coma vs. generalized tonic-clonic seizure: OR = 4.14, 95% CI 0.98-17.47, p = 0.053). In the high-dose (≥ 16 mg/day) groups, although distributions of modified Rankin Scale (mRS) scores were similar between perampanel responders and non-responders at discharge, a greater proportion of perampanel responders had less change in mRS scores from baseline than did perampanel non-responders (median mRS: 0 vs 4, p = 0.064). No cardiorespiratory adverse events or laboratory abnormalities were noted with perampanel treatment.

Conclusions: Perampanel is effective and has a satisfactory safety profile in the emergency treatment of established RSE and SRSE.