Haloperidol-induced torsade de pointes.

OBJECTIVE: To report a case of torsade de pointes related to the administration of high-dose intravenous haloperidol for the treatment of severe agitation. CASE
SUMMARY: Reports in the literature of intravenous haloperidol-induced torsade de pointes are rare. We describe the case of a 41-year-old white woman with no predisposing factors who developed torsade de pointes 55 minutes after a dose of intravenous haloperidol 80 mg (total dosage 915 mg over 7 d). The results of the electrocardiogram were consistent with torsade de pointes and showed a prolonged QTc interval of 610 milliseconds. Intravenous magnesium sulfate 2 g/100 mL NaCl 0.9% was administered, which controlled the arrhythmia. The patient received one additional 80-mg haloperidol dose six hours after the arrhythmia-triggering dose, without reoccurrence of torsade de pointes. Haloperidol was then discontinued, and the patient had no further arrhythmias.
CONCLUSIONS: Our case report and others from the literature suggest that intravenous haloperidol administration may prolong QT intervals in some patients, precipitating the potentially life-threatening arrhythmia torsade de pointes. Clinicians should be aware of haloperidol's potential to induce torsade de pointes, since it is used regularly for agitation and delirium in the critical care arena.