More than 10% of study patients taking antipsychotic drugs developed heart rhythm disturbances, and researchers recommend ongoing monitoring to manage cardiac risks.

According to a study published in the journal “Heart Rhythm”, the use of the antipsychotic drugs quetiapine and haloperidol is associated with an increased risk of ventricular arrhythmias and twice the risk of sudden cardiac death.

The risks of heart disease associated with use of antipsychotic drugs cause concern the last 30 years. The drugs have previously been either withdrawn from the market or restricted in use due to a very high risk of fatal ventricular arrhythmias. There are drugs that increase the risk of sudden cardiac death, but they remain on the market because they serve an important clinical need and there are no safer alternatives.

This research involved a retrospective analysis of the electronic medical records of a large group of patients in Taiwan who were treated with quetiapine or haloperidol. They found that more than 10% of patients experienced severe QT prolongation during follow-up, and they also found an increased risk of ventricular arrhythmias and sudden cardiac death.

“It would be prudent to perform an electrocardiogram before and after starting an antipsychotic medication. If possible, one could stop a drug that causes QT prolongation and try a different antipsychotic. But if that’s not practical, one should pay particular attention to reducing other risk factors,” says Professor Jamie Vandenberg, from Australia’s Victor Chang Cardiac Research Institute.