Widely prescribed drugs put dementia patients at greater risk of heart attacks, blood clots and pneumonia, a study has found.
The antipsychotic medications – often given to people with depression, agitation or aggression – may cause more serious side effects than previously thought.
Experts say the findings are so concerning that doctors should avoid prescribing medications such as Risperdal and Zyprexa and instead look to alternatives such as behavioral therapy.
Researchers examined data from 174,000 adult general practices in England on older adults diagnosed with dementia between 1998 and 2018.
About 35,339 people were prescribed antipsychotics during the study – 63 percent of whom were women – and their medical records were compared with those of dementia patients who were not prescribed these drugs.
Previous warnings from regulators when prescribing antipsychotics for these symptoms were based on evidence of increased risks of stroke and death, but evidence of other adverse effects was less convincing in people with dementia
Academics from the Universities of Manchester, Nottingham, Edinburgh and Dundee found that dementia patients who were current users of antipsychotic drugs had a two-fold increased risk of developing pneumonia compared to those who were not taking the drugs.
Researchers also found that dementia patients taking antipsychotics had a 61 percent increased risk of stroke and a 43 percent increased risk of breaking a bone.
They also found a 28 percent increased risk of heart attack and a 27 percent increased risk of heart failure.
Patients with dementia who were prescribed antipsychotic medications appeared to have a 72 percent increased risk of kidney damage and a 62 percent increased risk of developing a type of blood clot called venous thromboembolism.
Professor Darren Ashcroft, from the University of Manchester and senior author of the study, said: ‘In recent years it has become clear that more and more people with dementia are being prescribed antipsychotics, despite existing safety warnings in the regulations.
‘It is important that any potential benefits of antipsychotic treatment are carefully weighed against the risk of serious harm, and treatment plans should be reviewed regularly in all health and care settings.’
The increased risks appeared highest in the first week after treatment, according to the observational findings published in the BMJ.
The authors said their figures suggest that during the 180 days after starting the drugs, antipsychotic use may be associated with one additional case of pneumonia for every nine patients treated and one additional heart attack for every 167 patients treated.
Charles Marshall, professor of clinical neurology at Queen Mary University of London, said: ‘This evidence should prompt renewed efforts to reduce the prescribing of antipsychotics to people with dementia.’
Dr. Sheona Scales, research director at the charity Alzheimer’s Research UK, said: ‘The distressing symptoms of dementia, such as confusion and agitation, pose a significant challenge for people with dementia, their families and caregivers.
‘Treatments that can help control these symptoms are essential for a better quality of life, but options are currently limited and in certain circumstances antipsychotics may be used to treat severe symptoms.
‘However, these new findings suggest that these risks may be more serious than previously thought, which is especially concerning given the increase in their use during the pandemic.’