The association between intravenous haloperidol and prolonged QT interval

Area of Science:

• Cardiology
• Psychiatry
• Clinical Pharmacology

Background:

• Intravenous haloperidol (HAL) is frequently used for agitation.
• Reported cases of torsade de pointes and QT prolongation exist with intravenous HAL.
• The association between intravenous HAL, QT prolongation, and ventricular tachyarrhythmia requires further investigation.

Purpose of the Study:

• To investigate the association between intravenous HAL and QT prolongation.
• To assess the link between intravenous HAL and ventricular tachyarrhythmia.
• To evaluate the clinical significance of QT prolongation induced by intravenous HAL.

Main Methods:

• A cross-sectional cohort study was conducted.
• Corrected QT intervals (QTc) were measured before and after intravenous HAL administration.
• Electrocardiographic (ECG) findings were continuously monitored post-administration.

Main Results:

• The mean QTc was significantly longer 8 hours after intravenous HAL compared to flunitrazepam (FZ) alone (p < 0.001).
• QTc prolongation moderately correlated with the dose of intravenous HAL (r = 0.48, p < 0.001).
• No ventricular tachyarrhythmia was detected in 307 patients monitored for at least 8 hours.

Conclusions:

• QTc prolongation associated with intravenous HAL appears modest and not directly linked to dangerous ventricular tachyarrhythmias.
• Continuous ECG monitoring did not reveal ventricular tachyarrhythmia in the study cohort.
• Clinicians should remain aware of the potential for QT prolongation with intravenous HAL, especially in predisposed individuals.