Comparison of the effect of citalopram, bupropion, sertraline, and tricyclic antidepressants on QTc: A cross-sectional study.

Background: Some data suggests that citalopram has more risk of corrected QT interval (QTc) prolongation than other selective serotonin reuptake inhibitors. Consequently the U.S. Food and Drug Administration distributed a safety warning limiting the maximum dose for citalopram. There is also a suggestion that bupropion may decrease QTc in patients on drugs that increase QTc. The goals of this cross-sectional study were to examine (1) effects on QTc of citalopram compared to sertraline, bupropion, and tricyclic antidepressants; (2) dose dependent effects of citalopram; and (3) effects of bupropion on citalopram-mediated changes in QTc.

Methods: Records of subjects who received an EKG while taking one of the specified antidepressants were reviewed to collect demographic information, antidepressant history, and information about other confounders. Linear regression was used to examine the relationship between QTc and antidepressants.

Results: 487 subjects provided 798 EKG records. The sample was 95% male with an average age of 61 years. No differences were found in QTc between citalopram and other antidepressants. No dose relationship was detected between citalopram and QTc. Bupropion did not affect the relationship between citalopram and QTc (coefficient = -3.4; 95%CI = -14.2, 7.5; p = 0.54).

Limitations: Observational study designs are prone to biases from retrospective data collection. Some data subsets had small numbers of subjects.

Conclusions: No effect of citalopram on QTc was found at therapeutic doses. Neither was there evidence of a "QTc-sparing" effect of bupropion. The risk of adverse cardiovascular effects from citalopram at doses of 60 mg per day or less appears minimal.