The safety profile of the dual orexin receptor antagonists (DORAs) are currently unknown with regard to nocturnal responsivity among people with insomnia. We compared the auditory awakening thresholds (AATs) of the DORA suvorexant (10 and 20 mg) versus placebo in 12 individuals with DSM-5 insomnia.
The study used a double-blind, placebo-controlled, three-way crossover design. Participants were randomly assigned to a treatment sequence that included placebo, suvorexant 10 mg, and suvorexant 20 mg. At the time of maximum drug concentration, auditory tones were played during stable stage N2 sleep. Tones increased by 5-decibel (db) increments until the participant awakened. The db at awakening was recorded as the AAT and compared between conditions. The proportion of awakenings higher than 85 db was also compared between conditions. Finally, sensitivity analyses were also conducted using surrounding thresholds (80 db and 90 db).
The mean AAT did not differ significantly between either dose of suvorexant compared to placebo. Moreover, the proportions of individuals who remained asleep at the AAT 85 db cutoff did not differ across conditions. In addition, wake after sleep onset decreased and total sleep time increased in the suvorexant 20 mg condition compared to placebo.
Suvorexant (10 and 20 mg) preserved the ability to respond to nocturnal stimuli, whereas the 20-mg dose improved the sleep of people with insomnia. This suggests that DORAs such as suvorexant can effectively treat insomnia while allowing patients to awaken to nocturnal stimuli in the environment.
Clinical Trial Registration:
Registry: ClinicalTrials.gov; Title: A Phase IV 3-Way Double-blind, Randomized, Crossover Study to Compare the Awakening Threshold Effects (Responsivity) of Belsomra 10 mg and 20 mg to Placebo in Non-elderly Insomniacs; Identifier NCT03312517; URL: https://clinicaltrials.gov/ct2/show/NCT03312517.
Drake CL, Kalmbach DA, Cheng P, Roth T, Tran KM, Cuamatzi-Castelan A, Atkinson R, SinghM, Tonnu CV, Fellman-Couture C. Can the orexin antagonist suvorexant preserve the ability to awaken to auditory stimuli while improving sleep? J Clin Sleep Med. 2019;15(9):1285–1291.