Antipsychotics spiking cardiac risks: Study

Doctors are being urged to undertake an ECG before and after prescribing antipsychotic drugs, with new research shining a light on their links to heart health.
 
Researchers at the Victor Chang Cardiac Research Institute (VCCRI) found quetiapine and haloperidol were associated with an increased risk of ventricular arrhythmias, as well as doubling a patient’s risk of sudden cardiac death.
 
Published in Heart Rhythm, the authors undertook a retrospective analysis of electronic medical records of Taiwanese patients recently prescribed quetiapine or haloperidol.
 
They found up to 10% of patients developed severe QT prolongation, putting potentially thousands of patients at risk.
 
VCCRI Deputy Director Professor Jamie Vandenberg said that while the study focused on just two drugs, many others shared the same risk.
 
‘The risks of cardiac arrhythmias associated with the use of antipsychotics have long been known but we now finally know the scale of the problem in a real-world setting, and we need to try and reduce the risk and manage people more closely,’ he said.
 
‘If it is an option, one could stop a drug causing QT prolongation and try a different antipsychotic.
 
‘But if this is not practical, one should pay particular attention to reducing other risk factors, such as the prescription of other drugs that may exacerbate QT prolongation and be vigilant for hypokalaemia.’
 
Researchers said particularly for older patients, doctors must follow up regularly after prescribing antipsychotics.
 
Dr Anthony Marinucci, Chair of RACGP Specific Interests Aged Care, told newsGP the study adds weight to a well-established link between certain antipsychotics and increased risk of arrhythmia and sudden death. 
 
‘It is extremely important that all patients, including the elderly, are monitored for potential cardiac adverse effects whilst prescribed antipsychotic medication,’ he said.
 
‘Before commencing, all patients should have a baseline ECG, including QT interval measurement.
 
‘This study, and the associated risk found, should only further emphasise the importance for thorough screening and monitoring of cardiac disease in those patients requiring antipsychotics.’
 
About one in every 200 adult Australians will experience a psychotic illness each year, with the first episode most likely to happen in a person’s late teens or early adult years.
 
The most prevalent psychotic illness in Australia, schizophrenia, impacts around 2.4 per 1000 people and is slightly more common in men compared to women.
 
For those living with such conditions, medication, psychological therapy, and community support remain the most-used tools to help manage symptoms. 
 
Currently, about 350,000 Australians are prescribed at least one antipsychotic medication each year.
 
With this use of medication widespread, a team of researchers is now working to improve the safety of a range of drugs found to disrupt the heart’s normal rhythm.
 
Already they have begun developing computer modelling to better predict the cardiac safety of new drugs.
 
Dr Marinucci’s advice to GPs is to ensure all appropriate assessments are completed before starting a patient on a new antipsychotic medication.
 
‘A thorough and complete risk-benefit assessment should be performed on all patients before commencing antipsychotic medication,’ he said.
 
‘This includes screening for pre-existing cardiac disease and potential medication interactions.
 
‘Always start with the lowest effective dose whilst monitoring for signs or symptoms of adverse effects.’
 
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arrhythmia cardiovascular disease heart failure mental health