Antidepressants and the Risk of Ischemic Stroke in Older Adults According to the Degree of Serotonin Reuptake Inhibition: A Retrospective Cohort Study.

OBJECTIVE:The effects of serotonin reuptake inhibition induced by antidepressants on ischemic stroke and its pathophysiology remain unclear despite the frequent use of antidepressants and high fatality of ischemic stroke. We estimated the risk of ischemic stroke associated with antidepressant use in older adults according to the degree of serotonin reuptake inhibition. DESIGN:Retrospective cohort study. PARTICIPANTS:The cohort consisted of older adult patients who were treated with antidepressants. MEASUREMENTS:We estimated the risk of ischemic stroke associated with antidepressant use in older adults according to the degree of serotonin reuptake inhibition using Korea's National Health Insurance System-Senior Cohort. Exposure to antidepressants was categorized by type (strong, intermediate, or weak serotonin reuptake inhibitors [SRIs]) and by the mean prescribed dose per day and treatment duration. The risk for the strong and intermediate SRIs group was compared with that of the weak SRIs group using a Cox proportional hazards regression model. RESULTS:Of 97,411 were weak SRIs users, and 107,152 and 18,783 were users of strong and intermediate SRIs. The risk of ischemic stroke was 1.192- and 1.057-fold higher in strong and intermediate SRI users, respectively than in weak SRI users. Hazard ratios were increased in higher dose and shorter duration user groups. The risk increased 1.753-fold in strong SRI users with anticonvulsants and 1.387-fold in intermediate SRI users with PPIs. CONCLUSION:The use of strong and intermediate SRIs should be considered carefully in older adult patients, especially when high-dose antidepressants are prescribed even for a short duration.