Can Haloperidol (Haldol) prolong the QT interval?

From the Guidelines

Yes, Haldol (haloperidol) can prolong the QT interval on an electrocardiogram (ECG), and this effect is a significant concern due to the potential risk of Torsades de Pointes, a life-threatening heart rhythm disorder. The risk of QT prolongation with Haldol is dose-dependent, with higher doses posing a greater risk, and intravenous administration carries a higher risk than oral dosing 1. Patients with pre-existing cardiac conditions, electrolyte abnormalities (especially low potassium or magnesium), or those taking other QT-prolonging medications are at increased risk for this side effect 1.

Key Considerations

• Haldol blocks potassium channels in heart cells, affecting cardiac repolarization and extending the QT interval 1.
• The mechanism of QT prolongation with Haldol involves the inhibition of potassium channels, which can lead to a heterogeneous prolongation of repolarization across the myocardium, increasing the risk of Torsades de Pointes 1.
• Healthcare providers should obtain baseline ECGs before starting Haldol, monitor QT intervals during treatment, maintain normal electrolyte levels, and consider alternative medications in high-risk patients 1.
• The risk of Torsades de Pointes with Haldol is increased in patients with risk factors such as female gender, hypokalemia, bradycardia, and recent conversion from atrial fibrillation 1.

Clinical Implications

• Haldol should be used with caution in patients with risk factors for QT prolongation and Torsades de Pointes.
• Alternative medications should be considered in high-risk patients.
• Close monitoring of QT intervals and electrolyte levels is essential during Haldol treatment.
• Healthcare providers should be aware of the potential risk of Torsades de Pointes with Haldol and take steps to minimize this risk.

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 Yes, Haldol (haloperidol) can prolong QT intervals, especially at higher than recommended doses 2. Key points to consider:

• QT-prolongation and Torsades de pointes have been reported in patients receiving haloperidol
• Higher doses of haloperidol are associated with a higher risk of QT-prolongation
• Particular caution is advised in treating patients with other QT-prolonging conditions

From the Research

Haldol and QT Prolongation

• Haldol, also known as haloperidol, is a medication that has been linked to a risk of QTc-prolongation, which can lead to Torsade de Pointes and sudden cardiac death 3, 4, 5, 6.
• Studies have shown that patients taking haloperidol often have multiple risk factors for QTc prolongation, including concomitant use of other QTc-prolonging drugs, electrolyte abnormalities, and underlying cardiac conditions 3, 5.
• The risk of QTc prolongation with haloperidol is a concern, particularly in vulnerable populations such as critically ill patients and those with pre-existing cardiac conditions 7.
• Research has investigated the effect of haloperidol on QTc interval in various populations, including patients with delirium managed with oral and intravenous haloperidol 7, and patients receiving intravenous haloperidol for agitation 6.
• While some studies have found an association between intravenous haloperidol and QTc prolongation 6, others have found that low-dose intravenous haloperidol may not be clinically relevant for the development of a newly onset long QT syndrome or adverse outcomes 7.

Risk Factors and Management

• Risk factors for QTc prolongation with haloperidol include concomitant use of other QTc-prolonging drugs, electrolyte abnormalities, and underlying cardiac conditions 3, 5.
• Management of the risk of QTc prolongation with haloperidol includes electrocardiogram monitoring, particularly in patients with risk factors for QTc prolongation 3, 4.
• Clinicians should be aware of the association between intravenous haloperidol and QT prolongation, and take steps to minimize this risk, including monitoring electrocardiograms and adjusting doses as needed 6.