Factors Contributing to Increased Fall Risk in Patients Administered Orexin Receptor Antagonists

Background and Objective Orexin receptor antagonists (ORAs) are increasingly used as hypnotic sedatives. Compared to γ-aminobutyric acid receptor agonists, ORAs lack muscle-relaxant properties and are associated with a lower risk of falls. However, falls do occur in small numbers. We aimed to determine factors correlated with fall risk in patients administered ORAs.Methods Data of hospitalized patients administered suvorexant or lemborexant between January 1, 2022 and December 31, 2023 were retrospectively analyzed. Patients already taking medications upon hospitalization and those with unknown height or weight were excluded. Falls were identified through incident reports. Propensity-score matching was conducted based on demographics and clinical background, followed by statistical analysis. Logistic regression was applied to factors with p<0.2.Results Of 2,348 patients, 1,324 were eligible for analysis. After propensity-score matching, 66 patients were in the falls group and 132 in the non-falls group. Antidepressant use was significantly more common in the falls group (p=0.017) than in the non-falls group. Antidepressant use was associated with increased fall risk (odds ratio [OR], 14.40; p=0.016), whereas comorbid depression was protective (OR, 0.04; p=0.022). No significant associations were found for lemborexant use, benzodiazepine use, heart failure, or schizophrenia.Conclusions Antidepressants increase fall risk in ORA users, whereas comorbid depression may prevent falls.