Selective Serotonin Reuptake Inhibitor Use and Risk of Arrhythmia: A Nationwide, Population-Based Cohort Study

Purpose: This study compares the risks of arrhythmia among patients with depression receiving selective serotonin reuptake inhibitors (SSRIs) and those receiving other classes of antidepressants and among patients with depression receiving citalopram-escitalopram and those receiving other SSRIs. Methods: This retrospective cohort study used data from the 2000–2011 National Health Insurance Research Database in Taiwan. Patients with depression who were new antidepressant users were included in the study sample. Propensity score matching was used to balance the covariates between the comparison groups. Crude incidence rates were generated by Poisson regressions, and Cox proportional hazards regression models were used to assess the rates of arrhythmia among SSRI users and nonusers of SSRI antidepressants as well as between citalopram-escitalopram users and users of other SSRIs. Findings: Neither SSRI (hazard ratio [HR] = 0.95; 95% CI, 0.83–1.08) nor citalopram-escitalopram (HR = 1.20; 95% CI, 0.95–1.51) exposure was associated with a risk of arrhythmia compared with other, newer non-SSRI antidepressants or noncitalopram SSRIs. An increase in mortality was, however, observed among citalopram-escitalopram users (HR = 1.21; 95% CI, 1.08–1.31). Implications: Citalopram, escitalopram, and other SSRIs were not associated with an elevated risk of arrhythmia compared with each other or with non-SSRI antidepressants. Nevertheless, citalopram and escitalopram were associated with an increase in mortality risk compared with other SSRIs and deserve further investigation.