A Systematic Evaluation of the QTc Interval and Antidepressants in Youth: An Electronic Health Record Study

The US Food and Drug Administration announced that citalopram was associated with dose-related prolongation of the QTc interval in adults. This study aimed to assess how antidepressants affect QTc intervals in children. The authors hypothesized that some antidepressants would show an association with QTc prolongation.

An electronic medical record review was conducted of children aged 5 to 18 years in the Partners Healthcare system with at least 1 prescription of an antidepressant or methadone between February 1990 and August 2011. The authors extracted lifetime diagnoses and QTc interval of patients who had received an electrocardiogram 14 to 90 days after antidepressant or methadone prescription (N = 297). The mean QTc per medication was calculated as compared with the mean of all QTc measurements across medications. The number of patients taking medications who had QTc values in normal, borderline, abnormal, or high were also calculated.

Mean QTc values for all medications were in the normal range. The highest mean QTc was in patients on escitalopram (436 milliseconds). The mean QTc for sertraline (416 milliseconds) was significantly lower than all other drugs measured (t(331) = -2.21, p < .05). After controlling for confounding effects, none of the differences in mean QTc compared with other study drugs reached statistical significance. The greatest percentages of abnormal and high QTc values were found among patients taking paroxetine (18.8%), followed by escitalopram (15.4%). None of the children had documented ventricular arrhythmia.

The results suggest that most antidepressants are not associated with prolonged QTc at doses typically prescribed for children.