Association between antidepressant drugs and falls in older adults: A mediation analysis in the World Health Organization's pharmacovigilance database.

OBJECTIVES

The objective is to investigate the association between antidepressant drugs intake and falls reporting, as well as the potential mediators in-between, in older adults.

METHODS

In VigiBase®, the World Health Organization's pharmacovigilance database, we performed a disproportionality analysis to probe the putative associations between each antidepressant drugs class (non-selective monoamine reuptake inhibitors [NSMRIs], selective serotonin reuptake inhibitors [SSRIs], serotonin-norepinephrine reuptake inhibitors [SNRIs], alpha-2-adrenergic receptor antagonists, and "other antidepressants") and reports of falls in people aged 65 and over (NCT05628467). The reporting odds ratios and their 95% confidence interval were derived from logistic regression models with adjustment for confounders. We studied the falls-inducing mechanisms (delirium, hyponatremia, hypotension) by using causal mediation analyses and by using a disproportionality analysis for the co-occurrence of falls and these events.

RESULTS

Our main analysis included 86,200 cases of falls reporting in older adults (of which 57% were 75 and over). A significant association was found between falls and every antidepressant drugs class, except for NSMRIs. According to causal mediation analysis, a direct effect on the falls reports was shown for alpha-2-adrenergic receptor antagonists and for "other antidepressants". According to the co-reports analyses, all antidepressant drugs classes except SNRIs were associated with the co-event fall-delirium; SSRIs, alpha-2-adrenergic receptor antagonists, and "other antidepressants" with fall-hypotension; all antidepressant drugs classes except NSMRIs with fall-hyponatremia.

CONCLUSIONS

In multivariate disproportionality analyses, all antidepressant drugs classes were associated with signals of disproportionate reporting of falls in older adults, except for NSMRIs. In mediation analyses, a direct effect on the falls reports was only found for alpha-2-adrenergic receptor antagonists. Single-mediators based models seem insufficient to explain the diversity of clinical settings resulting in falls. These findings underline the necessity of a comprehensive analysis of all clinical and pharmacological features in older falling adults treated with antidepressant drugs.