The effect of lemborexant on insomnia in patients with psychiatric disorders: Detailed evaluation using the Athens Insomnia Scale

Aim: Chronic insomnia disorder is common and associated with reduced quality of life. Benzodiazepine hypnotics are commonly prescribed for insomnia, but have potential side effects such as concentration impairment, somnolence, and dependence. Lemborexant (LEM) is an orexin receptor antagonist considered to have fewer side effects than benzodiazepine hypnotics. This study evaluated the effect of LEM on sleep in detail and examined whether benzodiazepine hypnotics can be gradually tapered by adding LEM. Methods: We retrospectively examined the effectiveness of LEM in 28 outpatients with insomnia. Insomnia symptoms were assessed using the Athens Insomnia Scale (AIS) before and after LEM administration. We also attempted to taper benzodiazepine hypnotics and assessed benzodiazepine dose using diazepam equivalents for some patients taking benzodiazepine hypnotics. Wilcoxon's signed-rank test was used for statistical analysis. Results: The mean AIS score was significantly improved after LEM treatment (8.7 +/- 5.2 vs. 3.8 +/- 3.3; P < 0.01). Among the AIS subitems, significant improvement was observed for six items: sleep induction, awakenings during the night, sleep quality, well-being, functioning capacity, and sleepiness during the day. The mean benzodiazepine dose was significantly lower after LEM treatment (4.6 +/- 5.0 mg vs. 2.1 +/- 3.3 mg; P < 0.01). Conclusions: This study indicated the potential of LEM for improving insomnia and reducing benzodiazepine dose.