13 Effects of Benzodiazepines on Orthostatic Blood Pressure in Older People

Abstract

Abstract Background 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 the relationship between BDZs and orthostatic blood pressure (BP) behaviour in older people is scarce. We investigated the effects of BDZs on BP response to an orthostatic active stand test. Methods 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 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 624 community-dwelling people who underwent a clinic assessment, orthostatic active stand data was collected in 541. Information on regular BDZs use was available in 538 people. Of 538 participants, mean age was 72.7±7.2, 67.7% were female and 33 (6.1%) reported regular use of BDZs. History of falls (p=0.027) and fear of falling (p<0.001) were more prevalent in this subgroup. During active stand, participants on BDZs showed a significantly greater systolic BP drop 10 seconds after the posture change (“immediate” BP drop). No significant differences were detected in orthostatic systolic BP in the latter phases of the active stand. After adjusting for possible confounders, BDZs use was independently associated with a mean immediate systolic BP drop of 12 mmHg after standing. Conclusion BDZs may confer higher risk of an immediate systolic BP drop after standing in older people, which may contribute to their known falls risk. BDZ should be avoided in older people at risk of falling.