Abstract

Abstract Background New sleep-inducing drugs (eg, ramelteon, suvorexant, and lemborexant) have been shown to prevent delirium in high-risk groups. However, no single study has simultaneously evaluated the delirium-preventing effects of all novel sleep-inducing drugs in hospitalized patients. Therefore, this study aimed to clarify the relationship between sleep-inducing drugs and delirium prevention in patients hospitalized in general medical-surgical settings for nonpsychiatric conditions who underwent liaison interventions for insomnia. Methods This retrospective cohort study included patients treated in general medical-surgical settings for nonpsychiatric conditions with consultation-liaison psychiatry consult for insomnia. Delirium was diagnosed by fully certified psychiatrists using the Diagnostic and Statistical Manual of Mental Disorders 5 th edition. The following items were retrospectively examined from medical records as factors related to delirium development: type of sleep-inducing drugs, age, sex, and delirium risk factors. The risk factors of delirium development were calculated using adjusted odds ratios (aORs) via multivariate logistic regression analysis. Results Among the 710 patients analyzed, 257 (36.2%) developed delirium. Suvorexant (aOR, 0.61; 95% confidence interval [CI], 0.40–0.94; P = 0.02) and lemborexant (aOR, 0.23; 95% CI, 0.14–0.39; P < 0.0001) significantly reduced the risk of developing delirium. Benzodiazepines (aOR, 1.90; 95% CI, 1.15–3.13; P = 0.01) significantly increased this risk. Ramelteon (aOR, 1.30; 95% CI, 0.84–2.01; P = 0.24) and Z-drugs (aOR, 1.27; 95% CI, 0.81–1.98; P = 0.30) were not significantly associated with delirium development. Conclusions The use of suvorexant and lemborexant may prevent delirium in patients with a wide range of medical conditions.