Risk factors for QT prolongation associated with acute psychotropic drug overdose

Abstract Background Antipsychotic/Antidepressant use is a risk factor for QT interval (QT) prolongation and sudden cardiac death. However, it is unclear which drugs are risk factors for QT prolongation and torsades de pointes in cases of psychotropic drug overdose. Methods After correction of QT data by Bazett formula (QTc), QTc was classified into 3 categories (QTc Results A total of 649 patients were enrolled in the study. The independent risk factors for QTc prolongation were therapeutic and toxic range of phenotiazine antipsychotic drug (therapeutic range: odds ratio [OR], 1.56 [ P = .039]; toxic range: OR, 3.85 [ P P = .018). In addition, toxic range of phenotiazine antipsychotic drug (OR, 3.87; P = .012) and tricyclic antidepressants (OR, 4.94; P Conclusions The possibility of QT prolongation and torsades de pointes due to overdose of phenotiazine antipsychotic drug or tricyclic antidepressants requires particular consideration.