We searched in the PubMed, Cochrane, and Embase databases for randomized controlled trials (RCTs), and observational studies that evaluated the efficacy of suvorexant in preventing delirium in hospitalized patients, particularly postoperatively. Pooled analyses were conducted using random effects models with 95% confidence intervals (CI). Statistical analysis was performed using the RStudio Software, version 4.4.1.

A total of 3 RCTs, and 9 observational studies with 3,547 patients evaluated Suvorexant versus control. Suvorexant reduced delirium incidence (14.12% vs. 26.17%; OR 0.51; 95% CI 0.39 to 0.67; p=0.000001; I²=0%), and Ramelteon with Suvorexant reduced it even further (25.71% vs. 39.14%; OR 0.26; 95% CI 0.17 to 0.38; p<0.000001; I²=0%). Hospital mortality showed no significant difference between groups (4.21% vs. 9.58%; OR 1.22; 95 % CI 0.21 to 7.3; p=0.825; I²=81%). ICU stay was also non-significant (MD -0.25 days; 95% CI -1.11 to 0.62; p=0.573, I²=66%). Ventilation time was reduced by 4.26 hours (MD -4.26h; 95% CI -8.04 to -0.47; p=0.027; I²=95%). Time to delirium showed no statistic difference (MD -0.03 days; 95% CI -1.31 to 1.26; p=0.966; I²=89%).

This meta-analysis suggests that suvorexant was considered effective in reducing the incidence of delirium in hospitalized patients, particularly in postoperative settings.