Reconciling the risk of QT interval prolongation in antidepressants.

摘要

We discovered your article as a result of seeking answers to the myriad of theoretical and practical questions raised in response to a recent Food and Drug Administration (FDA) decision regarding citalopram. This decision is based in part on after-market case reports to the FDA and in part on a randomized, multi-center, double-blind, placebo-controlled, crossover study of 119 subjects receiving citalopram 20 mg per day (Day 9), citalopram 60 mg per day (Day 22), and placebo. At 20 mg per day, the average QTc (the interval between the beginning of an elec-trocardiographic QRS complex and the peak of the subsequent T wave, corrected for heart rate) was increased by 8.5 milliseconds and at 60 mg daily by 18.5 milliseconds. Based on this, the FDA advised against the use of citalopram above 40 mg daily. To quote, "As a result of this thorough QT study, the FDA has determined that citalopram causes dose-dependent QT (the interval between the beginning of a QRS complex and the peak of the subsequent T wave) interval prolongation and should no longer be used at doses above 40 mg per day."