EFFECTS OF BENZODIAZEPINES ON ORTHOSTATIC BLOOD PRESSURE IN OLDER PEOPLE

Abstract

Objective: Older people taking benzodiazepines (BDZs) have higher risk of falling, which is mainly attributed to unfavorable drug-related effects on cognition and psychomotor functioning. BDZs may also have hypotensive effects, but evidence concerning their consequences on orthostatic blood pressure (BP) behaviour is scarce. We investigated the association between BDZs and BP response to an active stand test in older people. Design and method: We performed a retrospective analysis of data from an outpatient research clinic in an Irish university hospital, where people aged 60 or older underwent a comprehensive geriatric assessment between August 2007 and May 2009. Non-invasive beat-to-beat orthostatic BP was measured during an active stand, with systolic BP assessed at each 10-second interval. Information on regular BDZs use was collected. Factors independently associated with orthostatic systolic BP were investigated using multiple linear regression. Results: Of 538 participants (67.7% female, mean age 72.7 ± 7.2), 33 (6.1%) reported regular use of BDZs. During active stand, participants taking BDZs showed a significantly greater systolic BP drop 10 seconds after the posture change (“immediate” BP drop), while no significant differences were detected in orthostatic systolic BP in the latter phases of standing. After adjusting for possible confounders, BDZs use was independently associated with a mean immediate systolic BP drop of 12 mmHg after standing. Conclusions: Older people taking BDZs may have higher risk of an immediate systolic BP drop after standing, adding to other BZD-related falls risks. BDZs should be avoided in older people at risk of falling.