Risks of antipsychotics for dementia ‘more severe’ than previously thought

Medics should be “cautious” when prescribing antipsychotic medication for dementia patients, experts have said, after a new study found that using the drugs can put patients at risk of a horde of different health conditions.

Experts said that the side effects linked to antipsychotics for dementia patients “may be more severe than previously understood”.

Antipsychotic drugs may be prescribed for people with dementia who develop aggression and psychosis, but these drugs are usually only prescribed after other drugs have been tried such as antidepressants, antidementia or anticonvulsant drugs.

The new study, published in The BMJ, examined data from 174,000 adults GP surgeries in England on older adults who were diagnosed between dementia between 1998 and 2018.

Some 35,339 were prescribed antipsychotics during the study – 63% of whom were women – and their medical records were compared to dementia patients who were not prescribed these drugs.

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.

They also found a 28% increased risk of heart attack and a 27% increased risk of heart failure.

Patients with dementia who were prescribed antipsychotics appeared to have a 72% increased risk of kidney injury and 62% increased risk of developing a type of blood clot called a venous thromboembolism.

Experts said that the increased risks appeared to be highest in the first week after treatment.

The authors said that their figures suggest over the 180 days after starting the drugs, use of antipsychotics might be associated with one additional case of pneumonia for every nine patients treated and one additional heart attack for every 167 patients treated.

The study is observational, so no firm conclusions can be made about cause and effect, but the authors wrote: “The range of adverse outcomes was wider than previously highlighted in regulatory alerts, with the highest risks soon after initiation of treatment.”

“It is important that any potential benefits of antipsychotic treatment are weighed carefully against the risk of serious harm, and treatment plans need to be regularly reviewed in all health and care settings.”

Commenting on the study, Dr Sheona Scales, director of research at the charity Alzheimer’s Research UK, said: “The distressing symptoms of dementia, such as confusion and agitation, pose significant challenges for people living with dementia, their families, and caregivers.

“Treatments that can help manage these symptoms are essential for a better quality of life, but options are currently limited, and in certain circumstances antipsychotics can be used to treat severe symptoms.

“However, these new findings suggest that these risks may be more severe than previously understood, which is particularly concerning given the rise in their use during the pandemic.”

Alzheimer’s Society associate director of research, Dr Richard Oakley, said: “This new evidence reinforces the risks of antipsychotic drugs and our previous calls to reduce their dangerous overprescribing.

“They should only ever be considered as a last resort for treatment.”

Charles Marshall, professor of clinical neurology at Queen Mary University of London, added: “This evidence should prompt renewed efforts to reduce the prescribing of antipsychotics to people living with dementia.”

Dr Tom Russ, honorary consultant psychiatrist at the University of Edinburgh, added: “This study does not suggest to me that these medications should never be used, but they should be used sparingly in situations where other avenues have been explored.”

Masud Husain, professor of neurology at the University of Oxford, said: “These findings add to existing evidence about the need to be cautious in prescribing antipsychotics to people with dementia.”