Anticholinergic Burden

Anticholinergic Burden

 As part of a series of blog posts surrounding World Patient Safety Day 2022's theme of 'Medication Safety', RSA for the East of Scotland and Consultant Urological Surgeon Andrew Martindale looks at anticholinergic burden. 

This year’s WHO Patient Safety Day 2022 focuses on medication safety with the aim of furthering the goals and achievements of the existing WHO Patient Safety Challenge: Medication without Harm. In 2017 the launch of this initiative highlighted polypharmacy as one of three priority areas in medication safety. Elderly patients with underlying comorbidity and chronic conditions may well already be receiving many long-term medications when they present for surgical treatment. In addition, pharmacological treatments commenced during surgical care may contribute to increasingly complex polypharmacy and potential cumulative effects.

In urology, this is particularly pertinent to the treatment of urinary urge. Anticholinergic medications are frequently used in the treatment of overactive bladder (OAB) in patients with or without incontinence. Whilst lifestyle changes in fluid management, caffeine reduction and intervention such as bladder retraining and physiotherapy are the recommended and often successful initial treatments, anticholinergic medications form the first line pharmacological therapy in many guidelines and have a proven record of improvement in quality of life for patients with OAB.

As prescribers, or those advising prescribing of drug therapies, we must ensure that we comply with best practice such as that outlined by the GMC: Good Practice in prescribing and managing medicines and devices. These include a responsibility to be informed about the efficacy of the medicines we recommend and their adverse effects. Common adverse effects of anticholinergic medication (dry mouth, constipation, impaired cognition) are well recognised, and severity is dose dependent. In addition to those used in urinary disorders, a wide range of commonly prescribed drugs (including antidepressants, antipsychotics, sedatives, antiparkinsonian drugs amongst others) have anticholinergic properties to varying degrees and are commonly prescribed in older patients. As the blood-brain barrier permeability increases with age, older patients become more susceptible to the central nervous system effects of anticholinergics such a blurred visions, dizziness, and confusion, leading to greater risk of falls and need to seek further medical attention.

Recognition of the increasing, cumulative effect of these multiple medications leading to an overall anticholinergic burden (AB) on elderly, co-morbid patients, predates the WHO patient safety challenge in 2017. In one Scottish region (NHS Tayside) the use of anticholinergic medication was seen to have increased by 24% in 2010, with 7% of patients classified as carrying a high anticholinergic burden. Polypharmacy, including AB, is a priority patient safety issue in NHS Scotland. Serial guidance has been published since 2012, with a third edition: Polypharmacy Guidance, Realistic Prescribing, a website and app now in place to support prescribers and patients. This provides a structured 7 step patient-centred process to help deal with polypharmacy, reduce risk and increase the safety of prescribing.

Urologist, uro-gynaecologists, and General Practitioners are therefore likely to encounter elderly patients in need of treatment for OAB, where anticholinergic medication is indicated, who may already have a significant AB. In 2017 a published questionnaire study suggested that awareness in healthcare professionals of this cumulative effect of multiple medications and relative contribution to overall AB was lacking. More recently, case control studies, systematic review and a 2021 Cochrane library review have found a consistent link between the use of anticholinergic medication and risk of future dementia. This had raised overall awareness of AB. However, comparison of studies, translation to the individual patients, and the relative effect of individual compounds is complicated by the range of scoring systems for AB, with disagreement on the differing relative contributions that should be allocated to different medications.

Although lack of awareness of the concept of, and consequences of, AB have been cited, this is only part of the solution; practical steps to reduce AB must be taken. In OAB, it is imperative that guidelines consider the increasing evidence for potential adverse effects of AB in the context of the proven benefits. Highly effective, non-pharmacological interventions are primary in most guidance on OAB but are often not the focus of clinician-patient interaction. Guidelines should provide clear signposting where alternative classes of drug (b-3 agonists, with no recorded anticholinergic activity) can be considered as well as which specific steps in a pathway may not be suitable for individual patients. Simple employment of an agreed scoring system for AB, and full awareness of the alternatives would best place the health care professional in a position to advise patients before anticholinergic prescription.

Safe, realist prescribing of anticholinergics for the individuals with OAB must emphasise the option for non-pharmacological treatment and alternatives to drug therapy, but also the potential significant positive effect medication can have on the quality of life of the patients with severe urinary urge or incontinence. The engagement of the RCSEd through the Patient Safety Group, in this year’s WHO Patient Safety Day is a real opportunity to increase awareness and promote ongoing research to the goal of effective and safe prescribing in OAB, and for all our patients on anticholinergic medication.

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