Is Haldol (Haloperidol) safe in patients with prolonged QT interval?

From the Guidelines

Haldol is not recommended for patients with prolonged QT interval due to its potential to further prolong the QT interval and increase the risk of torsades de pointes. According to the 2013 clinical practice guidelines for the management of pain, agitation, and delirium in adult patients in the intensive care unit 1, antipsychotics like haloperidol should be withheld in patients at high risk for torsades de pointes. The guidelines suggest that the risk of torsades de pointes is high in patients with baseline prolongation of the QT interval, those receiving concomitant medications known to prolong the QT interval, or those with a history of this arrhythmia.

The mechanism behind this effect involves haloperidol's ability to block potassium channels in cardiac cells, which disrupts normal repolarization of the heart. Patients with heart disease, electrolyte disturbances, or those taking other QT-prolonging medications are at particularly high risk and should generally avoid Haldol if possible. The 2006 acc/aha/esc guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death also list haloperidol as a medication that can cause QT prolongation and increase the risk of torsades de pointes 1.

Some key points to consider when managing patients with prolonged QT interval include:

• Avoiding medications that can further prolong the QT interval, such as haloperidol
• Correcting electrolyte abnormalities, particularly potassium and magnesium
• Using alternative antipsychotic medications with less impact on cardiac conduction
• Monitoring ECG regularly, especially when initiating or changing medications
• Considering temporary pacing or intravenous magnesium to manage torsades de pointes if it occurs. The 2018 aha/acc/hrs guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death also emphasizes the importance of avoiding QT-prolonging medications in patients with long QT syndrome 1.

Overall, the risk of torsades de pointes associated with haloperidol use in patients with prolonged QT interval is significant, and alternative treatments should be considered to minimize this risk. The use of Haldol in patients with prolonged QT interval should be avoided if possible, and if used, it should be done with extreme caution and close monitoring.

From the FDA Drug Label

Cases of sudden death, QT-prolongation, and Torsades de pointes have been reported in patients receiving haloperidol. Higher than recommended doses of any formulation of haloperidol appear to be associated with a higher risk of QT-prolongation and Torsades de pointes Although cases have been reported even in the absence of predisposing factors, particular caution is advised in treating patients with other QT-prolonging conditions

• QT-prolongation is a risk associated with haloperidol, especially at higher than recommended doses.
• The drug label advises particular caution in patients with other QT-prolonging conditions.
• Therefore, Haldol is not okay for prolonged QT, as it may increase the risk of QT-prolongation and Torsades de pointes 2.

From the Research

Haldol and Prolonged QT Interval

• Haldol, also known as haloperidol, is a typical antipsychotic medication that has been associated with QT interval prolongation 3, 4, 5, 6.
• The QT interval is a measure of the time it takes for the heart's ventricles to prepare for a new beat, and prolongation of this interval can increase the risk of cardiac arrhythmias and sudden death 3, 5.
• Studies have shown that haloperidol, particularly when administered intravenously, can cause QTc interval prolongation in a significant proportion of patients 4, 6.
• The risk of QTc interval prolongation with haloperidol is increased in patients with certain risk factors, such as:
  • Female sex 5
  • Existing heart disease 3, 5
  • Electrolyte abnormalities 3, 6
  • Hepatic insufficiency 3
  • Concomitant use of other QTc-prolonging medications 4, 6
• The frequency of adverse events associated with drug-induced QT interval prolongation is unknown, but it is estimated that the frequency of QTc prolongation in psychiatric patients is around 8% 5.
• Clinicians should be aware of the potential risks of QTc interval prolongation with haloperidol and take steps to minimize these risks, such as:
  • Monitoring electrocardiograms (ECGs) before and during treatment with haloperidol 4, 6
  • Avoiding concomitant use of other QTc-prolonging medications 4, 6
  • Correcting electrolyte abnormalities 3, 6
  • Using alternative medications with a lower risk of QTc interval prolongation, such as aripiprazole, brexpiprazole, or olanzapine 7