Characteristics of psychiatric patients with nightmares after suvorexant administration: A retrospective study.

Aim: Suvorexant is an orexin receptor antagonist (ORA) for the treatment of insomnia. The antagonistic action of suvorexant on orexin receptors is associated with an increase in rapid eye movement (REM) sleep, which can potentially lead to nightmares depending on the patient's condition. However, the precise risk factors for nightmares among patients taking ORAs, such as suvorexant, have yet to be identified. In this retrospective study, we aimed to identify the risk factors for the development of nightmares in patients treated with suvorexant.

Methods: The risk factors were determined by comparing parameters between the nightmare group and the nonnightmare group. This study included 440 patients who received suvorexant at the University of Miyazaki Hospital from April 2014 to January 2021.

Results: We found that 9.1% (n = 40) of the patients experienced suvorexant-induced nightmares. There was a significant difference in the median age, which was lower in the nightmare group than in the nonnightmare group (p < 0.01). Furthermore, both multiple logistic regression analysis and Cox proportional hazards regression analysis revealed increased odds ratios for nightmares for individuals aged 20-39 years.

Conclusions: This study revealed that elderly patients taking suvorexant had fewer nightmares than nonelderly patients did.