Prolongation of the corrected QT and torsades de pointes cardiac arrhythmia associated with intravenous haloperidol in the medically ill.

Consultation psychiatrists are frequently called upon by their medical and surgical colleagues to assist in the management of agitated, delirious patients in the intensive care unit. Intravenous haloperidol has a reputation for safe and effective sedation of these patients and has been found to be free of many of the dangerous anticholinergic and cardiac side effects of the lower-potency neuroleptics. The authors report the cases of three patients who developed torsades de pointes arrhythmia or lengthening of the Q-T interval during treatment with intravenous haloperidol. The cases suggest that the use of intravenous haloperidol should be accompanied by cardiac monitoring and that risk factors for torsades de pointes during haloperidol treatment may include dilated cardiomyopathy and a history of alcohol abuse.