Perampanel in chronic insomnia

Abstract

Objectives: Insomnia is the most prevalent sleep disorder in the general population, and one of the most frequent reasons for consultation in the Sleep Units. Perampanel is an antiepileptic also effective on the structure of sleep, and in restless legs syndrome. We describe the first study that evaluates perampanel in patients with chronic insomnia.

Patients and methods: Observational retrospective cohorts study of 66 patients with chronic resistant insomnia, 33 exposed to perampanel, other 33 as non-exposed group. All patients attended in Neurology or Psychiatry Consultation, from November 2017 to November 2018. Patients included had been treated with more than 4 different drugs in the previous 4 years. We reviewed age, sex, insomnia etiology, years of evolution, number of previously used drugs, and the results of perampanel for insomnia after 3 months of treatment in the exposed cohort, measured by the improvement of 3 or more points in the ISI and Pittsburgh scales, as well as the average of hours of sleep gained. Non-exposed patients were matched with this variables, but never treated with perampanel.

Results: We have included 66 patients. In the exposed cohort: we describe 33 patients with chronic resistant insomnia, 20 women (60 %), 13 men (40 %). Average age 53.48 years, average time of evolution: 11.25 years. Main etiology: depression 13 cases (40 %). After the combination of perampanel 2-4 mg (100 %) with antidepressants (17 cases, 51.5 %) or anxiolytics (12 cases, 36.36 %) along 3 months: the total number of hours of sleep improves in 2.5 h, the scale ISI improves by 6 points (± 2.1 SD, p = 0.02), and Pittsburgh scale improves in 4 points (± 1.7, p = 0.04). In non-exposed cohort, the improvement of the ISI scale was 2.2 points (±0.8, p = 0.06), on the Pittsburgh scale was 1.6 points (± 0.5, p = 0.01). The main adverse effect was irritability in 3 patients, without withdrawal perampanel. The treatment was abandoned by 4 patients (12.12%): 1 due to persistent irritability (3%), 2 due to lack of efficacy (6 %), 1 due to pregnancy wish (3 %).

Conclusion: The combination of Perampanel with an antidepressant, or an anxiolytic, improves the quality of sleep measured by ISI and Pittsburgh scales (statistically significant), probably due to its antagonistic action on glutamate. A clinical trial compared with placebo would be necessary to corroborate these results.

Keywords: Antiepileptic drug; Chronic insomnia; ISI scale; Perampanel; Pittsburgh scale; Resistant insomnia; Sleep scales.