A critical evaluation of the cardiac toxicity of citalopram: part 1.

In August 2011, the U.S. Food and Drug Administration issued a safety announcement that the antidepressant drug citalopram (Celexa(®)) should not be used at dosages greater than 40 mg per day (or greater than 20 mg per day for patients 60 and older) because it can cause abnormal changes in the electrical activity of the heart. This warning was based on the results of a "thorough QT/QTc study" of citalopram and on post-marketing reports of QT prolongation and torsade de pointes in some patients taking the drug. The statistically significant results from the "thorough QT/QTc study" were small in magnitude, and their clinical significance is questionable. Additional electrocardiogram analyses from other studies do not confirm these findings. Nearly 600 cases of citalopram overdoses have been described. Although citalopram overdose is not entirely "cardiac safe," only a proportion of patients develop QTc prolongation without serious cardiac sequelae and no deaths. Three studies comparing citalopram overdoses to other antidepressant overdoses do not demonstrate clinically meaningful differences in cardiotoxic effects.