Skip to content
Umbrella Aged Care
← Medicines and deprescribing

Anticholinergic burden

GPs & clinicians Aged care staff 6 min read

By Dr Josh Hatch, FRACGP

Anticholinergic medicines block the action of acetylcholine, a chemical messenger in the brain and the rest of the body. The combined effect of all such medicines a person takes is called the anticholinergic burden 24. A high burden is linked with dementia in observational studies, but trials of reducing it have not yet shown a benefit to thinking or memory 2224.

Numbers in the text link to the 4 sources listed at the foot of this page.

Medicine groups linked with dementia risk

In a large English study, the groups below were each associated with higher odds of a later dementia diagnosis at the highest level of exposure. The figures are adjusted odds ratios from an observational study 22.

  • Bladder antimuscarinics. Odds ratio 1.65 (95% CI 1.56 to 1.75). Oxybutynin is a common example 22.

  • Anticholinergic antidepressants. Odds ratio 1.29 (95% CI 1.24 to 1.34). Amitriptyline is a common example 22.

  • Antipsychotics. Odds ratio 1.70 (95% CI 1.53 to 1.90) 22.

  • Antiparkinson medicines. Odds ratio 1.52 (95% CI 1.16 to 2.00) 22.

  • Antiepileptics. Odds ratio 1.39 (95% CI 1.22 to 1.57) 22.

What the observational evidence shows

The study was a nested case-control analysis of English primary care records, comparing 58,769 people diagnosed with dementia with 225,574 matched controls aged 55 and over. People with the highest cumulative exposure to strong anticholinergic medicines over the previous 1 to 11 years had higher odds of dementia (adjusted odds ratio 1.49, 95% CI 1.44 to 1.54), and the association was stronger in people diagnosed before the age of 80 22.

This is an association, not proof that the medicines cause dementia. The authors tested longer gaps between exposure and diagnosis, to reduce the chance that early symptoms of dementia were driving the prescriptions, and the results were similar 22.

The trial evidence

Reducing anticholinergic burden to improve thinking and memory

Uncertain / conflicting

Trials have lowered the burden but have not shown better cognition. They were small and short.

The evidence

A 2023 Cochrane review found three trials with 299 participants, followed for one to three months. The certainty of evidence was very low, the reviewers could reach no conclusion about cognitive outcomes, and there was no trial evidence of benefit for mortality, quality of life, function or falls 24. In a Norwegian trial of 87 residents in 22 nursing homes, pharmacist-initiated changes after multidisciplinary review lowered the anticholinergic score in the intervention group, but word recall and other cognitive measures were no better at eight weeks 23. A 2024 review of nine deprescribing trials that measured the Drug Burden Index, which combines anticholinergic and sedative load, found no overall difference in the change in the index in community or nursing home settings, and inconsistent effects on cognition 25.

In practice

Short trials in small groups could miss a slow benefit 2324. Stopping a medicine that is no longer needed has value of its own, whatever its effect on memory.

Putting it together

The case for reviewing these medicines rests on their known short-term effects and on the observational link with dementia, not on trials showing that stopping them improves memory 2224.

Scores such as the Drug Burden Index turn a resident’s medicines into a single number, which can help in spotting residents with a high load. For a resident with dementia, the dementia section’s medicines page lists common anticholinergic medicines and a sequence for reviewing them.

Related pages on this site

Sources cited on this page

  1. 22 Coupland CAC, Hill T, Dening T, Morriss R, Moore M, Hippisley-Cox J. Anticholinergic drug exposure and the risk of dementia: a nested case-control study. JAMA Intern Med. 2019;179(8):1084–93. (English primary care data; observational.) View source
  2. 23 Kersten H, Molden E, Tolo IK, Skovlund E, Engedal K, Wyller TB. Cognitive effects of reducing anticholinergic drug burden in a frail elderly population: a randomized controlled trial. J Gerontol A Biol Sci Med Sci. 2013;68(3):271–8. (87 residents, 22 Norwegian nursing homes.) View source
  3. 24 Taylor-Rowan M, Alharthi AA, Noel-Storr AH, et al. Anticholinergic deprescribing interventions for reducing risk of cognitive decline or dementia in older adults with and without prior cognitive impairment. Cochrane Database Syst Rev. 2023;12:CD015405. (3 randomised trials, 299 participants.) View source
  4. 25 Liu BM, Redston MR, Fujita K, Thillainadesan J, Gnjidic D, Hilmer SN. The impact of deprescribing interventions on the Drug Burden Index and other outcomes: a systematic review. J Am Med Dir Assoc. 2024;25(7):105021. (9 randomised trials.) View source

See every source cited across the medicines and deprescribing section →

Written by Dr Josh Hatch, FRACGP. General information only, reflecting his reading of the published evidence as at October 2026. It is not individual medical advice, does not create a doctor–patient relationship, and must not be used to start, stop or change any treatment. Evidence and Australian regulatory, PBS and program arrangements change — always confirm current advice with the treating GP, pharmacist or specialist.

This is general education, not a clinical protocol. The doctors who practise with Umbrella Aged Care are independent general practitioners, and each makes their own clinical decisions with the resident and family. Your GP’s advice for an individual may differ from what is written here. If it does, please ask them to talk it through with you.

Enquire about care