Effects of benzodiazepines on orthostatic blood pressure in older people

Background: Older people taking benzodiazepines (BDZs) have higher risk of falling, which is mainly attributed to cognitive and psychomotor effects. BDZs may also have hypotensive effects. We investigated the association between BDZs and orthostatic blood pressure behaviour in older people.

Methods: We retrospectively analysed data from an outpatient clinic where people aged 60 or older underwent a geriatric assessment. Non-invasive beat-to-beat orthostatic systolic blood pressure (SBP) was assessed at regular time intervals before and after an active stand test. We compared clinical characteristics between BDZs users and non-users and also investigated if BDZs use was an independent predictor of baseline SBP. Factors associated with SBP change were investigated using a repeated measures general linear model.

Results: Of 538 participants (67.7% female, mean age 72.7), 33 (6.1%) reported regular BDZs use. BDZ users had lower baseline SBP (149 versus 161 mmHg, P < 0.05). Multiple linear regression confirmed BDZs use as independent predictor of baseline SBP in N = =538. At 10 s post-stand, the SBP difference between BDZs use groups became maximum (21 mmHg); at this point, SBP still seemed to be decreasing in BDZ-users, whereas in controls it seemed to be recovering. After adjustment (age, sex, hypertension, frailty, comorbidity, antihypertensives), BDZs were associated with greater SBP reduction between baseline and 10 s post-stand (P < 0.05).

Conclusion: Older people taking BDZs may have a higher risk of orthostatic hypotension, perhaps due to an exaggerated immediate BP drop. This adds to other BDZ-related falls risks. BDZs should be avoided in older people at risk of falling.