51app

Intended for healthcare professionals

Practice Sustainable Practice

Reducing patient and planetary harms from high anticholinergic burden medication

51app 2024; 384 doi: (Published 15 January 2024) Cite this as: 51app 2024;384:e075708

Linked Editorial

Sustainable practice: what can I do?

  1. Honey Smith, salaried GP, clinical net zero lead, co-chair123,
  2. Hannah Fligelstone, FY2 doctor4
  1. 1Richmond Medical Centre, Sheffield, UK
  2. 2South Yorkshire Integrated Care Board
  3. 3Greener Practice Community Interest Company, Sheffield
  4. 4Mid-Yorkshire Hospitals NHS Trust, Wakefield
  1. Correspondence to H Smith honey.smith1{at}nhs.net

What you need to know

  • Prescribing medicines with high anticholinergic burden carries significant risk of adverse clinical outcomes for patients

  • Anticholinergic burden scores can be a useful way of assessing anticholinergic burden

  • Consider tapering when stopping anticholinergic medications to avoid withdrawal effects, which may include nausea and sweating

Overprescribing and polypharmacy have been identified as a risk to patients and the planet.1 Prescribing medications with a high anticholinergic burden carries significant risk for patients, particularly older people. The adverse outcomes that result from this also incur substantial carbon and planetary burdens which might be mitigated by deprescribing anticholinergic drugs where appropriate.

Why change is needed

Polypharmacy (the concurrent use of multiple medication items by one individual)2 in older people are becoming increasingly common.34 One common aspect of polypharmacy is high anticholinergic burden.56 When one or more drugs with anticholinergic properties are prescribed, the risk of adverse events combines and accumulates. Examples of medications with an anticholinergic burden (ACB) are shown in table 1.

Table 1

Commonly prescribed drugs with anticholinergic burden (ACB)

View this table:

Clinical implications

Drugs have different levels of anticholinergic effect. The extent of an individual’s ACB can be summarised through their ACB score, for which there are several validated ACB score calculators.7 The risks of anticholinergics increase with each additional point scored, with an increase in mortality associated with the number and ACB potency of the medication prescribed.9 A combined ACB score of 3+ (using, for example, the ACB calculator8) leads to an increased risk of admission for falls and fractures,10 cognitive decline,11 dry mouth, constipation, and blurred vision,12 outcomes to which older adults (and particularly those already at higher risk of dementia, falls, or frailty) are more vulnerable. ACB scores can give a useful guide to the risk of anticholinergic adverse events, although they do not consider drug dose, or offer an estimate of individual risk. A 2023 study13 found an association between recently raised anticholinergic burden and increased risk of acute cardiovascular events, with a greater increase in anticholinergic burden conferring higher risk.

Environmental impacts

Prescribing contributes 20% of the NHS’s carbon footprint14 because of the carbon costs of manufacture, packaging, distribution, and disposal. Reducing medications of questionable clinical benefit to the patient is one way to reduce the health system’s planetary footprint. Direct emissions from anticholinergic prescribing are unquantified.

The adverse clinical outcomes of high anticholinergic burden may also add to the carbon burden of care owing to increased healthcare usage; with healthcare attendances (to address side effects and the consequences of other serious harms), investigations (eg, blood tests and imaging for cognitive decline), more prescribing (of mouth care and constipation products, for example), and hospital admissions. A bed-day in hospital is estimated to have a carbon footprint of 125 kg CO2e, an outpatient appointment for acute care 77 kg CO2e, and a GP visit 66 kg CO2e.15

Evidence for the solution

The likely environmental benefits of reviewing anticholinergic burden have not been studied directly, hence are drawn from the known harms of anticholinergic medications and conclusions drawn from a systematic review undertaken in 2022.16 One study found that healthcare practitioner oriented interventions, such as structured medication reviews, were most effective in reducing ACB and drug burden, and promoted the discontinuation or reduction of anticholinergic medications. Another review found that ACB deprescribing resulted in a significant reduction in Drug Burden index scores, falls, and adverse drug reactions after six months.17

In the absence of direct evidence, potential alternatives to medication with anticholinergic burden can be considered. The carbon footprints of these alternative interventions are themselves unquantified, but modelling suggests that deprescribing offers economic benefits and a reduced carbon burden. For example, hospital admissions are costly in both financial and carbon terms.

What you can do

Medications with anticholinergic properties have a wide range of clinical benefits that may outweigh their side effects and potential risks for some patients. However, anticholinergic burden should be considered when first prescribing and at medication reviews.

Consider anticholinergic burden at initial prescription

Being aware of the anticholinergic burden of commonly used drugs can help clinicians bring this into shared decision making about treatment options at first presentation, and to consider alternative strategies. Consider specifically the patient’s frailty and their risk factors for falls and cognitive impairment. Table 2 outlines some alternatives to ACB medication for commonly prescribed indications.

Table 2

Examples of potential alternatives to medication with anticholinergic burden for specific indications

View this table:

Early review of patients after initiating anticholinergic medication

New medications that are not having a clinically meaningful benefit, or where side effects are outweighing benefits, can be stopped. Ask specifically about common anticholinergic side effects such as dry mouth, constipation, and falls.

Identify and review patients with a high anticholinergic burden

A patient centred consultation focusing on high ACB medication may identify areas for safe, gradual reduction or substitution of low ACB alternatives. Anticholinergic burden scores can be calculated ahead of a planned medication review using an online tool, and some electronic health records also include these calculators. Note that scores do not consider medication dosage or individual renal function, which may influence the anticholinergic burden in practice. A systematic review of ACB scores7 was unable to perform a meta-analysis to quantify the clinical risks of high scores.

Anticholinergic withdrawal syndrome, a clinical picture including nausea, sweating, agitation, confusion, and urinary urgency, can occur when people stop taking anticholinergic medications. Detailed guidance on tapering regimens for different groups of ACB drugs is available,26 but in general the longer the patient has been on the medication, the longer the tapering period.

Education into practice

  • Who at your practice could support you in implementing regular or more frequent anticholinergic medication reviews?

  • What potential barriers do you foresee in offering alternative interventions (as listed in table 2) rather than a medication with associated ACB?

How patients were involved in the creation of this article

No patients were directly involved in the creation of this article.

Footnotes

  • This article is part of a series that offers practical actions clinicians can take to support reaching net zero. Browse all the articles at . To pitch your idea for an article go to

  • Contributorship and the guarantor: HS and HF conceived the article and HS is the guarantor. Both authors wrote and reviewed the article. HS created the figure and tables. HS was the contact for patient involvement.

  • Competing interests: none declared. Both authors have completed the Unified Competing Interest form (available on request from the corresponding author) and declare: no support from any organisation for the submitted work, no financial relationships with any organisations that might have an interest in the submitted work in the previous three years, no other relationships or activities that could appear to have influenced the submitted work.

  • No ethical approval was required for this paper.

  • Provenance and peer review: Commissioned; externally peer reviewed.

References