No clear benefit with suvorexant for reducing delirium in hospitalized older adults

Treatment with the orexin receptor antagonist suvorexant does not appear to significantly reduce the incidence of delirium in hospitalized older adults when compared with placebo, according to data from a phase III study.

A total of 203 hospitalized Japanese adults between 65 and 90 years of age who were at high risk of delirium (mild cognitive impairment or mild dementia, history of delirium at prior hospitalization, or both) were included in the study.

These participants were randomly assigned to receive suvorexant 15 mg (n=101, mean age 81.5 years, 51.5 percent men) or placebo (n=102, mean age 82.0 years, 44.1 percent men), administered at bedtime, for up to 7 days while in the hospital. The primary endpoint of delirium (diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria while participants were hospitalized) was compared between the two treatment groups.

Delirium occurred in 17 participants in the suvorexant group and in 27 participants in the placebo group. While the number was higher in the placebo group, the between-group difference was not statistically significant (16.8 percent vs 26.5 percent; difference, −8.7 percent, 95 percent confidence interval, −20.1 to 2.6; p=0.13).

Likewise, the frequency of adverse events (AEs) was similar between the two groups. This was true for overall AEs, drug-related AEs, serious AEs, and discontinuations due to AEs. Commonly reported AEs, with the exception of delirium, were constipation, vomiting, nausea, and insomnia.

More studies are needed to establish the benefit of suvorexant for reducing delirium, particularly delirium with a hyperactive component, in a high-risk population of older adults.