bottle pillsAlmost a third of older people with learning disabilities in Ireland are being prescribed high levels of medicines with side effects that can negatively affect their health and quality of life, researchers have found. 

The research team from Trinity College Dublin and Aston University found that people with learning disabilities were commonly prescribed medicines described as having anti-cholinergic activity. These medicines block a key neurotransmitter called acetylcholine, which is involved in passing messages between nerve cells. While this action is necessary in some clinical circumstances it can lead to side effects including confusion, memory impairment, bladder problems, falls, increased heart rate, anxiety and restlessness. 

The findings, which use data from a long-term study of older adults with learning disabilities in Ireland, the IDS-TILDA study, are published in the British Journal of Psychiatry.

The study found that about 30% of the people studied were taking high levels of medicines with anti-cholinergic activity, defined as having an anti-cholinergic burden score of 5+.

Higher levels of anticholinergic usage compared to similar studies in older adults without learning disabilities; 50% of people with learning disabilities in the study were taking medicines with definite anti-cholinergic activity compared to 4% of older adults without learning disabilities in two similar studies in the general population.

More than a third of the medicines with a high anti-cholinergic score being taken by people with intellectual disabilities were antipsychotics – medicines originally developed to treat the symptoms of schizophrenia.

High levels of anti-cholinergic prescribing were associated with people in the study reporting side effects of daytime drowsiness and chronic constipation.

The authors commented that this first of its kind study highlights the need for comprehensive, regular reviews of medicine use to avoid inappropriate prescribing of multiple medicines, particularly anti-cholinergic medicine combinations. They also noted that initiatives to address concerns about the use of medicines with high anti-cholinergic activity in people with learning disabilities will also likely benefit all older people, especially those with dementia.

Professor Mary McCarron, principal investigator for IDS-TILDA and dean of the Faculty of Health Sciences, Trinity, said: “People with intellectual disabilities are at increased risk of more chronic illnesses as they grow older when compared to the general population. On the one hand, appropriate medication can help improve both longevity and quality of life. On the other hand, the use of multiple medications, in particular of psychotropic drugs, something more common in older adults with intellectual disabilities means that anti-cholinergic related side effects are of serious concern.”

Lead author and assistant professor in pharmacy practice in the School of Pharmacy and Pharmaceutical Sciences, Trinity, Dr Máire O’Dwyer, added: “The side effects from anti-cholinergic medicines can have a significant impact on quality of life for people with intellectual disabilities. If someone is experiencing day time drowsiness and chronic constipation among other side effects, that is bound to affect their ability to exercise, to socialise, to engage in society and go about their day to day activities. As people with intellectual disability continue to move away from institutional settings into community-based ones, their ability to stay active and connected is of increased importance.” 

Dr Ian Maidment, co-author and senior lecturer in clinical pharmacy at Aston University, said: “People with intellectual disabilities are amongst the most vulnerable members of society. Yet we found very high levels of anti-cholinergic usage compared with the general population. More worryingly such usage was associated with drowsiness and constipation; precisely the type of side effects we would want to avoid. Overall, this study adds to the increasing evidence that prescribing in people with intellectual disabilities is sub-optimal.”

Dr Martin Henman, co-author and associate professor of the practice of pharmacy, Trinity, added: “This study is notable not only because it is the first of its kind nor because it shows an association between the use of these medicines and patient outcomes, but also because it highlights the scale and scope of the problem. The medicines with anticholinergic activity recorded by participants are being used to treat a number of disorders and symptoms. Therefore, assessing the benefits that each medicine produces and balancing those with the risks that they create individually and cumulatively is a difficult set of problems. 

“It will require a multi-disciplinary team of health care professionals to be able to tackle these problems for each person. This study shows that establishing and empowering these teams must be a priority in order to optimise the use of medicines in the care of people with intellectual disability.”

McCarron concluded: “We actually know very little about how older people with intellectual disabilities respond to medications but IDS-TILDA will begin to answer important questions and map critical concerns as it does here with what is the first study to have investigated anticholinergic burden in ageing adults with intellectual disability.”