Orthostatic hypotension (
OH) is often reported as a significant potential adverse effect of
antidepressant use but the association between phasic blood pressure (BP) and
antidepressants has not yet been investigated. This cross-sectional study compares continuously measured phasic BP and prevalence of
OH in a cohort of
antidepressant users ≥50 years compared with an age- and sex-matched cohort not taking
antidepressants.
OH was defined as a drop in systolic BP ≥ 20 mm Hg or in diastolic BP ≥ 10 mm Hg at 30 seconds after standing, measured using continuous beat-to-beat finometry. Multilevel time × group interactions revealed significantly greater systolic and diastolic BP drop in
antidepressant users than nonusers at 30 seconds after stand. The prevalence of
OH among
antidepressant users was 31% (63/206), compared with 17% in nonusers (X2 = 9.7; P = .002). Unadjusted logistic regression models demonstrated that
selective serotonin reuptake inhibitor use was associated with
OH at an odds ratio of 2.11 (95% confidence interval: 1.25-3.57); P = .005, and this association was not attenuated when covariates including
cardiac disease and depressive symptom burden were added. There was no statistically significant association between
serotonin noradrenaline reuptake inhibitor or
tricyclic antidepressant use and
OH in unadjusted models although the study was not powered to detect changes within these subgroups. Older people taking
antidepressants have a two-fold higher prevalence of
OH than nonusers, highlighting the importance of screening the older
antidepressant user for
OH and
dizziness and rationalizing medications to reduce the risk of falls within this vulnerable cohort.