Clinical Audit - Identifying inappropriate anticholinergic medicine prescribing

Published: June, 2024 | Review date: June, 2027

Audit focus

The purpose of this audit is to assess anticholinergic burden in older patients who are prescribed anticholinergic medicines and determine if their current treatment is still appropriate.

Background

Anticholinergic medicines are indicated for range of medical conditions and include antidepressants, antihistamines, antipsychotics and medicines to treat urinary urgency and incontinence (Table 1). People who are prescribed multiple medicines with anticholinergic activity are at increased risk of adverse effects (e.g. dry mouth, blurred vision, urinary retention and drowsiness) and this cumulative anticholinergic influence is referred to as the anticholinergic burden, although it can occur with just one anticholinergic medicine. In New Zealand, more than 40% of people aged over 65 years are exposed to medicines with anticholinergic activity.¹ This group is more likely to experience anticholinergic burden due to age-related changes in physiology, and increased likelihood of multiple morbidities requiring management with anticholinergic medicines. To prevent unnecessary exposure to associated risks, anticholinergic medicines should only be prescribed to people with a specific clinical indication for treatment, and at the lowest effective dose for the shortest period of time.

Given the range of medical conditions that anticholinergic medicines are prescribed to manage, each clinician is likely to have a number of patients who are being treated with these medicines; some for longer than is recommended or with a higher dose than is necessary. These patients may benefit from a dose reduction or deprescribing, depending on the clinical scenario and the patient’s therapeutic goals and treatment preferences. Patients who still require pharmacological management may benefit from switching to medicines with lower or no anticholinergic activity, if available. Non-pharmacological interventions should also be prioritised to reduce the required dose of, or overall need for, anticholinergic medicines.

When deprescribing or switching medicines, gradual dose tapering of the original anticholinergic medicine may be required to limit withdrawal symptoms. A general “rule of thumb” for tapering anticholinergic medicines is to reduce the prescribed dose by 25 – 50% over a period of one to four weeks. Close monitoring is required over the tapering period for anticholinergic withdrawal symptoms (over the first one to three days) and recurrence of symptoms associated with the condition originally being treated (after approximately seven days). Patients who develop withdrawal symptoms or a reoccurrence of their original symptoms should restart the medicine at the lowest tolerated dose and reattempt a slower tapered reduction after 6 – 12 weeks. Alternate day dosing may be beneficial in situations where available medicine strengths are not appropriate for tapering. Clinicians should ensure that any anticholinergic medicines prescribed for short-term symptom management are not inadvertently continued, e.g. orphenadrine for muscle spasms associated with a lower back strain, promethazine for nausea and vomiting or motion sickness.

There will be some patients taking anticholinergic medicines long-term for whom reducing the dose or stopping the anticholinergic medicine is not appropriate, e.g. clozapine for schizophrenia. If required, medicines with anticholinergic activity should be prescribed at the lowest effective dose, for the shortest possible duration.

For further information on anticholinergic burden in older people, see: bpac.org.nz/2024/anticholinergic.aspx

1. Nishtala PS, Narayan SW, Wang T, et al. Associations of drug burden index with falls, general practitioner visits, and mortality in older people. Pharmacoepidemiology and Drug 2014;23:753–8. doi:10.1002/pds.3624.

Audit Plan

Summary

This audit identifies patients aged 65 years and over who are currently taking an anticholinergic medicine to assess their anticholinergic burden, whether the indication for treatment remains and if reducing the dose (or stopping or switching the medicine) is appropriate.

Recommended audit standards

Ideally, all patients who have been taking an anticholinergic medicine for longer than six months^* should have undergone an assessment of their anticholinergic burden and have documented evidence in their patient record of an indication for ongoing treatment or evidence of a discussion about stepping down to a lower dose or stopping completely. This audit identifies patients who are prescribed an anticholinergic medicine and should have their anticholinergic burden assessed.

^*The recommended duration of treatment for anticholinergic medicines varies depending on the condition being managed. Six months has been selected pragmatically for this audit to allow sufficient time for patients who are prescribed anticholinergic medicines, e.g. oxybutynin and solifenacin to treat urinary urgency and incontinence, to have experienced an improvement in symptoms.

Audit Data

Eligible patients

All patients aged 65 years or over who are prescribed at least one anticholinergic medicine are eligible for this audit.

Identifying patients

This is a “working audit” where the data sheet is filled in over time when you have a consultation for any reason with an eligible patient until the required number of patients has been reached.

Sample size

The number of eligible patients will vary according to your practice demographic. For the purposes of this audit, continue until at least ten eligible patients have been identified and included.

Criteria for a positive outcome

Anticholinergic burden should be assessed in a patient who is prescribed an anticholinergic medicine for longer than six months. If there is no record of a recent anticholinergic medicine assessment in the patient’s clinical notes, this should be undertaken at the time or planned for their next appointment – the audit entry for the patient should remain open until this is completed. The assessment should include evaluation of all anticholinergic medicines currently prescribed to the patient, any over-the-counter use of anticholinergic medicines, and any adverse effects they are experiencing that could be related to their use of anticholinergic medicines (e.g. falls).

Based on the results of the assessment, a decision should be made to continue prescribing the anticholinergic medicine because the patient has an ongoing indication and is benefiting from treatment, or that the patient would benefit more from reducing or stopping (or switching) the anticholinergic medicine because symptom relief is insufficient, or they are experiencing adverse effects.

Following the assessment, a positive result is achieved if the patient’s clinical notes contain:

• Documented evidence of assessment of anticholinergic burden in the last six months (either undertaken previously or as part of this audit); AND EITHER
• A record of a current indication for ongoing treatment with an anticholinergic medicine, e.g. diagnosis of urinary frequency, urgency or urge incontinence and symptom improvement when taking the anticholinergic medicine OR
• A record of a discussion with the patient about reducing the dose or stopping the anticholinergic medicine completely, or switching to an alternative medicine with lower anticholinergic activity (if available)

Data analysis

Use the sheet provided to record your data. Aim to carry out an assessment of anticholinergic burden for as many eligible patients as possible.

Using clinical audits for improving practice and patient outcomes

Clinical audits can be an important tool to identify where gaps exist between expected and actual performance. Once completed, they can provide ideas on how to change practice and improve patient outcomes. General practitioners are encouraged to discuss the suitability and relevance of their proposed audit with their practice or peer group prior to commencement to ensure the relevance of the audit. Outcomes of the audit should also be discussed with the practice or peer group; this may be recorded as a learning activity reflection if suitable.

The Plan, Do, Study, Act (PDSA) model is recommended by the Royal New Zealand College of General Practitioners (RNZCGP) as a framework for assessing whether a clinical audit is relevant to your practice. This model has been widely used in healthcare settings since 2000. It consists of two parts, the framework and the PDSA cycle itself, as shown in Figure 1.

Figure 1. The PDSA model for improvement.

Source: Plan, Do, Study, Act (PDSA) cycles and the model for improvement

1. The framework

This consists of three questions that help define the “what” and “how” of an improvement project (in this case an audit). The questions are:

• "What are we trying to accomplish?" – the aim
• "How will we know that a change is an improvement?" – what measures of success will be used?
• "What changes can we make that will result in improvement?" – the concept to be tested

2. The PDSA cycle

This is often referred to as the “engine” for creating, testing and carrying out the proposed changes. More than one cycle is usually required; each one is intended to be short, rapid and frequent, with the results used to inform and refine the next. This allows an ongoing process of continuous learning and improvement.

Each PDSA cycle includes four stages:

• Plan – decide what the change to be tested is and how this will be done
• Do – carry out the plan and collect the data
• Study – analyse the data, assess the impact of the change and reflect on what was learned
• Act – plan the next cycle or implement the changes from your plan