A study led by researchers from Queen’s University Belfast has found anticholinergic drugs significantly increase the risk of mortality in people with dementia. The research has been published in Ageing & Mental Health.

In 2015, over 47 million people worldwide were living with dementia and this figure is expected to increase to 66 million in 2030, and 115 million in 2050. People with dementia are more likely to be taking medications for a range of diseases and/or illnesses than people without dementia. Moreover, some of these comorbidity medications are likely to have anticholinergic properties.

Dr Alan McMichael, Researcher from the Centre for Public Health at Queen’s University and first author on the paper, said: “The aim of this study was to examine the risk of mortality associated with anticholinergic use among those with dementia. We looked specifically at people in Northern Ireland, as this had never been studied before.

“We already know there is a link between anticholinergic use and a higher risk of developing dementia or cognitive impairment, but little is known about the link between anticholinergic use and whether they influence mortality rates among people with dementia.”

The researchers looked at data from the Enhanced Prescribing database for 25,418 people who were prescribed at least one dementia management medication between 2010 and 2016. Information was also extracted on the number of times each available anticholinergic drug was prescribed between 2010 and 2016, allowing the calculation of an overall anticholinergic burden (which refers to the cumulative effect of taking one or more medications with anticholinergic activity).

The study found that higher anticholinergic burden in people with dementia was associated with significantly higher mortality rates in comparison to people with dementia who had no anticholinergic burden. The researchers found that of the 25,418 people with dementia, only 15 per cent had no anticholinergic burden. Diazepam (42 per cent) and risperidone (18 per cent) were found to be the two most commonly-prescribed drugs, and respiratory and urological drugs in particular significantly increased mortality rates among people with dementia.

The results also found people with dementia living in areas with low levels of deprivation had a significantly lower anticholinergic burden, while those living in rural areas had a higher anticholinergic burden compared to those living in urban areas.

Dr Bernadette McGuinness, Researcher from the Centre for Public Health at Queen’s, Consultant Geriatrician at the Belfast Health and Social Care Trust and senior author on the paper, said: “These findings are especially important for the people of Northern Ireland, but are also highly relevant for people with dementia, their families, carers and healthcare professionals worldwide.

“We hope this discovery will pave the way for better understanding of the effect of anticholinergic drugs and lead to better treatment options for people with dementia. Further research should address the unfavourable prognosis of people living with dementia in highly deprived areas to improve their life expectancy.”