Antidepressants and risk of postural hypotension: a self-controlled case series study in UK primary care

Abstract

Background Antidepressants are associated with postural hypotension (PH), but it is not typically recognised as a common adverse effect. PH is linked with serious complications in older adults, for example, falls, stroke, and cognitive decline. Randomised controlled trials (RCTs) examining antidepressants often exclude older people and do not focus on adverse effects. Aim To examine the risk of PH associated with antidepressant use in adults aged ≥60 years in UK primary care. Design and setting A self-controlled case series using routinely collected primary care data from the IQVIA Medical Research Database (IMRD) from 1 January 2000 to 31 December 2018. Method Data from >41 000 adults aged ≥60 years in IMRD between 1 January 2000 to 31 December 2018 were obtained. Antidepressant prescriptions were determined using code lists based on British National Formulary classification. Risk of PH was examined during four exposure risk periods (90-days pre-prescription; day 1–28; 29–56; and ≥57) compared with periods outside these risk windows. Results Among 41 005 people with incident PH in the study period, 8899 (22%) were prescribed a selective serotonin reuptake inhibitor (SSRI); 8313 (20%) were prescribed a tricyclic antidepressant (TCA); and 4656 (11%) were prescribed an ‘other antidepressant’. The authors observed a consistent increased risk of PH in day 1–28 in allantidepressant exposure, which reduced thereafter. Risk of PH was highest with SSRIs (incidence rate ratio [IRR] 4.22, 95% confidence interval [CI] = 3.76 to 4.74), followed by ‘other antidepressants’ (IRR 2.17, 95% CI = 1.76 to 2.68), and then TCAs (IRR 2.12, 95% CI = 1.79 to 2.50). Risk of PH reduced from day ≥28 for all antidepressants. Conclusion A statistically substantial increased risk of PH was observed with all antidepressants in the first month, particularly SSRIs. Prescribers should be aware of this risk and may consider monitoring PH when initiating antidepressants in older adults.