Web site: February 2010
Prescriber Update 2010;31(1):4-5
Prescribers are reminded that antipsychotics are associated with QT interval prolongation. The QT interval is the measure of time between the onset of ventricular depolarisation and completion of ventricular repolarisation. A prolonged QT interval is a risk factor for sudden cardiac death. A corrected QT interval (QTc) greater than 450ms in men and greater than 470ms in women is considered to be prolonged.
A European review classified these medicines into three categories according to the level of information on cardiotoxic risk.1
|Insufficient information||Intermediate information||Good information|
The data sheets for these medicines are being updated to include more information on the risk of QT interval prolongation. For medicines with good evidence of QT prolongation, it is recommended that they are not used in patients with:
Caution should also be used in patients with cardiovascular disease or a family history of QT prolongation. The need for ECG monitoring should be assessed on an individual patient basis.