Ziprasidone and Hypokalemia

Sir: Although concerns about sudden cardiac arrhythmia death associated with the use of an antipsychotic drug actually predate the description of torsades de pointes, it is this fatal arrhythmia and its electrocardiographic (ECG) predictor (corrected QT [QTc] interval prolongation) that have become of increasing concern related to the use of antipsychotic medications during recent years. The first case reports of patients dying from a fatal arrhythmia while taking an antipsychotic medication appeared in 1963,1 and 3 years later torsades de pointes was described.2 Although it would be some years before these 2 phenomena were linked, with similar cases mounting,3 the reality of antipsychotic medication–induced torsades de pointes has since become an entity that those prescribing these medications must guard against.