Orexin receptor antagonists for the treatment of insomnia and potential treatment of other neuropsychiatric indications.

In this review, we outline the role of orexin receptor antagonists in disorders of sleep/wake and other potential neuropsychiatric conditions, with a focus on suvorexant, which is currently the only approved agent in this class. The efficacy of suvorexant was established in Phase 2-3 trials with treatment durations ranging from 1 to 12 months in patients with insomnia. Suvorexant is effective at improving sleep assessed by patient self-report and by polysomnography, with generally little effect on underlying sleep architecture. The main side-effect is next day somnolence. With the growing realization of the important connections between sleep and other disorders, studies are ongoing to explore this novel mechanism in other disorders such as Alzheimer's disease and depression.