People with intellectual disability taking multiple medicines with side effects

Posted on: 22 September 2016

Researchers have found that almost one third of older people with intellectual disabilities in Ireland are being prescribed high levels of particular kinds of medicines with side effects which can negatively affect their health and quality of life.

The research team from Trinity College Dublin and Aston University, UK, found that people with intellectual disability 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 intellectual disability in Ireland, the IDS-TILDA study, have just been published in the British Journal of Psychiatry.

The study found:

  • Approximately 30% of the people studied were taking high levels of medicines with anti-cholinergic activity, defined as having an anti-cholinergic burden (ACB) score of 5+.
  • Higher levels of anticholinergic usage compared to similar studies in older adults without intellectual disability; 50% of people with intellectual disabilities in the study were taking medicines with definite anti-cholinergic activity compared to 4% of older adults without intellectual disabilities in two similar studies in the general population.
  • Antipsychotics, powerful medicines originally developed to treat the symptoms of schizophrenia, accounted for over one-third of the medicines with a high anti-cholinergic score being taken by people with intellectual disabilities.
  • 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 intellectual 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 noted: “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, Trinity, Dr Máire O’Dwyer said: “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 in Aston University, UK, who has published widely in this area 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 commented: “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.”

Dr Henman continued: “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.”

Professor Mary McCarron added: “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.”

The paper ‘Association of anticholinergic burden with adverse effects in older people with intellectual disabilities: an observational cross-sectional study” is available here:

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