Lemborexant Shift Work Treatment Study

Insomnia and daytime sleepiness are common complaints among night shift workers. A meta-analysis on sleep in shift workers indicates that fixed night shift workers sleep, on average, 0.4 hours less than fixed day shift workers, while rotating shift workers sleep on average 1 hour less than fixed day shift workers. While there may be several reasons for sleep difficulties and sleep loss among shift workers, the misalignment of one's sleep preference (i.e., goal of sleeping during the day) and one's circadian rhythm (i.e., endogenous rhythm that signals the body to be awake during the day) is thought to be a primary cause. Insufficient sleep among night shift and rotating shift workers is linked with significant health consequences, including elevated risk for cardiovascular disease and cancer. Effective sleep treatments in shift workers are lacking. However, a recent randomized study of Suvorexant (20mg), a hypocretin/orexin receptor antagonist, produced a significant improvement in daytime total sleep time compared to placebo. Available evidence suggests that the reason Suvorexant is effective is because it blocks the hypocretin/orexin receptors that mediate signaling from the biological clock (suprachiasmatic nucleus of the hypothalamus) attempting to maintain sustained wakefulness during the biological day. As Lemborexant is also a hypocretin/orexin antagonist, it would also be expected to improve daytime sleep in shift workers but would have the advantage over Suvorexant of being highly effective in the dosages available for clinical use. As such, Lemborexant is ideally positioned to be an effective and important treatment of sleep problems in shift workers. The aim of this Phase IV double-blind, placebo-controlled, randomized study is to test whether a dual orexin antagonist, Lemborexant (5mg or 10mg), which would be expected to block the clock-driven orexin-mediated wakefulness during the day, will increase daytime sleep time in shift workers who complain of difficulty sleeping during the daytime compared to placebo. This will be a 4-week double blinded placebo controlled trial (2 weeks of baseline assessment followed by 2-weeks of treatment/placebo). The trial design is based on a recent successful study of the treatment of sleep problems in shift workers with a hypocretin/orexin receptor antagonist.