Anticholinergic Medications

Medications that block the actions of the chemical acetylcholine are known as anticholinergic medications. Acetylcholine is an important chemical that allows communication between individual cells in the body. These communications help to maintain body temperature, control muscle contractions, and remember old and new memories.

Sometimes these drugs are chosen specifically for their ability to block acetylcholine. Other times, blocking this chemical is an unwanted side-effect.

These medications have a number of side effects including dry mouth, drowsiness, confusion and memory problems. These side effects are more likely to be experienced by older adults.

These medicines (anticholinergics) are often used by older people. It is suggested that almost two thirds of older people living in the community use one or more of these medicines. Medications with these properties are used to treat a range of conditions including: 

• Allergies
• Asthma
• Chronic obstructive pulmonary disease
• Depression
• Diarrhoea
• Insomnia
• Irritable bowel syndrome
• Motion sickness
• Muscle spasms
• Overactive bladder and urinary incontinence
• Parkinson’s disease
• Vomiting

​Antihistamines

• Cetirizine
• Chlorphenamine

Bladder Medications

• Oxybutynin

Pain Relief Mediciations

• Amitriptyline
• Codeine
• Dihydrocodeine

Diuretic/Water tablets

• Furosemide

Stomach/Indigestion Medications

• Ranitidine (Zantac)

Irritable Bowel/Nausea Medications

• Loperamide (Imodium)

Antidepressants

• ​​​​​​​Most antidepressants

We recently completed a 2-year project, funded by the Dunhill Medical Trust (Grant Number RPGF1806/66), to identify and review the available evidence behind the risks of anticholinergic medication use.  This was a collaboration of researchers from the University of Aberdeen, University of Glasgow and the University of East Anglia.

Our team’s research has shown that taking more anticholinergic medications are linked to a person’s risk of dementia, falls, physical impairments, reduced quality of life and death.

Here are some examples of our findings which have been published in scientific journals:

• Quinn, T.J., Myint, P.K., McCleery, J., Taylor-Rowan, M. & Stewart, C. (2020).  Anticholinergic burden (prognostic factor) for prediction of dementia or cognitive decline in older adults with no known cognitive syndrome.  Cochrane Database of Systematic Reviews, (2)
• Stewart C, Taylor-Rowan M, Soiza RL, Quinn TJ, Loke YK, Myint PK. Anticholinergic Burden Measures and Older Peoples’ Falls Risk: A Systematic Prognostic Review. Ther Adv Drug Safety (in revision)
• Stewart C, Yrjana K, Kishor M, Soiza RL, Taylor-Rowan M, Quinn TJ, Loke YK, Myint PK. Anticholinergic Burden Measures Predict Older People's Physical Function and Quality of Life: A Systematic Review. J Am Med Dir Assoc. 2021;22(1):56-64.  
• Graves-Morris K, Stewart C, Soiza RL, Taylor-Rowan M, Quinn TJ, Loke YK, Myint PK. The Prognostic Value of Anticholinergic Burden Measures in Relation to Mortality in Older Individuals: A Systematic Review and Meta-Analysis. Front Pharmacol. 2020;11:570.

One of our clinicians, Dr. Roy Soiza, was interviewed about our work and his concerns as a consultant geriatrician about the use of anticholinergic medications :

• David Knight: Prescription drugs and dementia - why we need to get to the truth of the issue | Press and Journal

Here is a video of Prof. Phyo Myint and Dr. Roy Soiza presenting some of our work at a University of Aberdeen Café Med event in 2019:

• Café MED: Less is more? A tale of Anticholinergics | University of Aberdeen - YouTube

Here are some further pieces of work which also support our findings in relation to the impact of these medications upon memory and dementia:

• Medications and thinking skills in later life | Age UK
• Investigating the links between anticholinergic drugs and benzodiazepines and risk of dementia | Alzheimer's Society

Our recent work also found that several pharmacist-led interventions have been tested to try to reduce patients use of anticholinergic medications. Each of these studies were successful in reducing patients use of these medications. However, none of the studies explored other outcomes such as improvements in health or quality of life. There were also gaps in explaining how the interventions worked or were applied.

• Nakham A, Myint PK, Bond CM, Newlands R, Loke YK, Cruickshank M. Interventions to Reduce Anticholinergic Burden in Adults Aged 65 and Older: A Systematic Review. J Am Med Dir Assoc. 2020;21(2):172-180.e5.

We tried to find out how patients, their carers and healthcare professionals viewed these interventions. We wanted to know what features or aspects were barriers and or facilitators to reducing anticholinergic medication use. We learned that few studies had explored this.

• Stewart C, Gallacher KI, Nakham  A, Cruickshank M, Newlands R, Bond CM, Myint PK, Bhattacharya D, Mair FS. Barriers and facilitators to reducing anticholinergic burden from the perspectives of patients, their carer’s and healthcare professionals: a qualitative systematic review. Int J Clin Pharm 2021.

In response to this we secured funding from the Chief Scientist Office (Scotland) and conducted several focus groups and interviews with healthcare professionals and patients.

• Cunningham Y, Wood K, Stewart C, Nakham A, Gallacher KI, Quinn TJ, Ellis G, Lowrie R, Myint PK, Bond C, Mair FS. Understanding stakeholder views regarding the design of an intervention trial to reduce anticholinergic burden. Front Pharmacol (in revision).

By minimising the number of anticholinergic medications a person takes, we think we may be able to reduce this risk and improve overall health and wellbeing. However, strong evidence supporting this concept is still not available.

We know that using these medications increases a person’s risk of falls, dementia and other problems. Stopping or reducing the dose of these medicines is possible, alongside switching to safer medicines or exploring non-medicine treatments. But we do not know the best way to do this or if doing so will improve older peoples’ health and wellbeing.

Our team continues to develop the knowledge to tackle this important issue. We plan to conduct further research to address the uncertainties. We need to know more about the benefits of reducing use of these medications to find out if such benefits can outweigh the risks.

Talk to your doctor if you have concerns about your anticholinergic medicines or you are experiencing unusual side effects. Our PPI group have developed a flyer and a short animated video (links below) to explain the importance of this and encouraging you to ask questions about your medications.

• Anticholinergic Medicines Video with subtitles
• Anticholinergic Medicines Video with audio description

It is recommended that people know and understand the medications that they themselves, or the person that they care for, are using. The World Health Organisation as part of their campaign in 2017 released this video encouraging everyone to play their part in improving the use of medications.

Here are some useful sources of information about why this important. This report commissioned by Age UK and published in 2019 highlights some of the issues experienced by older people in relation to the medications that they are using.

There is also advice available for carers from the Family Caregivers Alliance.