Prescribing antipsychotic drugs for dementia patients ‘more dangerous than thought’

Antipsychotic drugs given to patients with dementia are far more dangerous than thought, a major study has found.

Doctors are already told to be careful in prescribing such drugs, which are known to raise risk of death and should only be prescribed when other medicines have failed.

Such drugs have been dubbed “the chemical cosh” with concerns about misuse in care homes owing to their heavy sedative effects.

A study of 174,000 people published in the BMJ has found the medicine causes even more side effects than was thought.

Taking the drugs for three months increased the risk of heart attack or failure by more than a quarter, doubled the risk of pneumonia and caused large rises in kidney problems and blood clots.

The past decade has seen repeated efforts to curb the use of the drugs, which are supposed to only be prescribed to dementia patients suffering from agitation or psychosis if other medicines have failed.

Increase in prescriptions

Their use rose sharply during the pandemic, however, with a study in 2022 highlighting a 50 per cent increase in prescriptions of the drugs in care homes since 2018.

Experts called for more to be done to reduce the use of the drugs among the vulnerable.

The latest study examined data from older adults in England who were diagnosed with dementia between 1998 and 2018.

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

Academics from Manchester, Nottingham, Edinburgh and Dundee universities found that dementia patients who were current users of antipsychotic drugs had a twofold increased risk of developing pneumonia compared with those who were not taking the drugs.

Adverse outcomes

Researchers also found that dementia patients who took antipsychotics had a 61 per cent increased risk of stroke and a 43 per cent elevated risk of breaking a bone.

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

Patients with dementia who were prescribed antipsychotics appeared to have a 72 per cent increased risk of kidney injury and 62 per cent 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 of the study said: “The range of adverse outcomes was wider than previously highlighted in regulatory alerts, with the highest risks soon after initiation of treatment.”

Prof Darren Ashcroft, the senior author of the study who is from Manchester University, said: “In recent years, it has become clear that more people with dementia are being prescribed antipsychotic drugs, despite existing regulatory safety warnings.

“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.”

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 carers.

“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 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.”

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 living with dementia.”