Rational prescribing for ongoing management of asthma in adults
- Helen Reddel
- Aust Prescr 2012;35:43-6
- 1 April 2012
- DOI: 10.18773/austprescr.2012.022
Although asthma is one of the most common chronic conditions in Australia, current treatment often fails to reflect clinical practice guidelines.
Improving the patient’s management first requires an assessment of how well their asthma is controlled.
Factors such as poor inhaler technique and poor adherence may contribute to poor asthma control. These need to be addressed before adjusting the patient’s drug prescription.
Simple processes for step-up and step-down adjustments of treatment are used to maintain good control while minimising adverse effects.
There should be an emphasis on shared decision-making to improve patient understanding and acceptance of treatment.
Deaths from asthma have dramatically fallen in recent years, so asthma is now often perceived as a commonplace and rarely serious condition. However, treatment of asthma in Australia is not optimal. The majority of preventer prescriptions for asthma in adults (≥15 years) are for the highest potency combination of an inhaled corticosteroid and long-acting beta2 agonist rather than a low-dose inhaled corticosteroid (≤400 microgram/day budesonide or equivalent) which alone should be sufficient for most patients.1,2 In addition, more than half of the people aged 15–34 years are dispensed these medications only once in a year. Most patients use their inhalers incorrectly, and only 22% of patients have a written asthma action plan.1
Clinical outcomes and costs could be substantially improved if an evidence-based approach was taken to tailoring an individual’s asthma assessment and management.
Current asthma guidelines are based on assessment of the patient’s level of asthma control. This is the extent to which the effects of asthma have been reduced or removed by treatment.3 There are two important components.
The first component is the level of current control. This is determined by the frequency of symptoms, use of reliever inhalers and activity limitation over the last month, and spirometry. Simple assessment tools include the Asthma Score * , and the Global Initiative for Asthma (GINA) categorisation (controlled, partly controlled or uncontrolled).2 The level of control should be recorded at each visit to facilitate comparison. Sub-optimal current control is indicated by an Asthma Score
The second component of asthma control is the patient’s future risk of adverse outcomes, particularly exacerbations and adverse drug reactions. This may appear unnecessary, since patients with well-controlled symptoms generally have few exacerbations, and uncontrolled symptoms should prompt treatment review. However, additional risk factors for patients with few current symptoms are one or more exacerbations in the past year, any intensive care unit admission for asthma, low lung function, smoking, and long-term use of high-dose inhaled corticosteroids.3
In many chronic diseases, treatment is based on the initial disease severity, an intrinsic and relatively static feature. Previously, asthma ‘severity’ was based on the initial clinical features. However, patients with similar symptoms had widely differing responses to treatment. Asthma is now perceived as a syndrome with several underlying pathophysiological processes which are variably modified by inhaled corticosteroid treatment.
Asthma severity is now defined by the level of treatment required to achieve best asthma control.3 ‘Mild asthma’ can be well controlled on low-dose inhaled corticosteroids, but ‘severe asthma’ requires high-dose combination therapy or is uncontrolled despite such treatment.
Once or twice a year each patient’s asthma control and risk factors should be reviewed, and treatment adjusted if necessary. Patients may also make short-term adjustments for worsening asthma in accordance with their written action plan.
In general, clinical guidelines recommend that patients experiencing symptoms three or more times a week or with one or more exacerbations per year should commence regular low-dose inhaled corticosteroids, or step up their existing preventer treatment. However, before any step-up, some important factors should be considered.
Asthma symptoms are non-specific, and new symptoms may be due to other conditions such as rhinitis, cardiac failure or vocal cord dysfunction.4
Most patients and health professionals have incorrect inhaler technique, but are unaware of this.5 The only way to identify incorrect technique is to watch the patient using their inhaler ( see Box 1 ).
The inhaler device should not be changed simply because the patient’s technique is incorrect. Education about inhaler technique takes only 2–3 minutes, but is often very effective in improving asthma control6 and is valued by patients. A physical demonstration, either in person or by video, is essential to improve inhaler technique.7 Checklists and videos are available on the National Asthma Council website.5,8
Patients are often reluctant to admit to poor adherence. Permissive wording can assist, for example, ‘Would you usually take your inhaler once or twice a week, or less, or more?’. Poor adherence should not be surprising in asthma, with intermittent symptoms that usually respond rapidly to a reliever inhaler. In Australia, these medications are cheaper and more readily available than preventer medications, and patients often perceive them as safer.
Poor adherence may be classified as either intentional – where the patient makes a reasoned choice that the drug’s perceived risks outweigh its perceived benefits – or unintentional, due to forgetfulness9 or cost10.
There are few easy solutions to poor adherence. For unintentional poor adherence, suggest an alarm, placing the inhaler next to the toothbrush, or simplifying the medication regimen. Cost may be an issue, even for patients with a concession card.10 In this situation, consider the relative cost to the patient of different preventer options, and aim for regular daily use even if at a low dose. For intentional poor adherence, a discussion about perceived risks and benefits can identify key barriers. An agreed dose can be negotiated using shared decision-making and goal-setting strategies, with little increase in consultation times.
Before increasing treatment, consider if poor control is due to rhinosinusitis, smoking, occupational exposure, allergens or drugs such as beta blockers. For many triggers, reducing exposure is beneficial, but evidence for house dust mite avoidance strategies is limited. Breathing exercises can help to reduce anxiety-related symptoms or reliever overuse, but they do not improve lung function or airway inflammation.11
Consider a dose increase or add-on therapy only after dealing with other factors contributing to poor control. Handle any change as a therapeutic trial, and document the patient’s level of asthma control before and after the change. Set a review date, for example 2–3 months, and agree on criteria for assessing the patient’s response.3
For patients whose asthma is uncontrolled on low-dose inhaled corticosteroids, two different step-up regimens are available. One option is a conventional regimen of low-dose inhaled corticosteroid with a long-acting beta2 agonist, with a short-acting beta2 agonist for symptom relief. Currently, the Pharmaceutical Benefits Scheme requires that patients should first be stabilised on separate inhalers, rather than a combination inhaler. However, this requires an additional visit and may increase the chance that patients will only take the long-acting beta2 agonist.
The other step-up is a combination of low-dose budesonide and eformoterol (100/6 or 200/6), used as both maintenance and reliever therapy. This is possible because budesonide/eformoterol has a similar onset of action to salbutamol. With this regimen, levels of asthma control are similar and the risk of exacerbations is reduced or similar, versus higher-dose inhaled corticosteroid or inhaled corticosteroid/long-acting beta2 agonist.12 This apparent paradox is probably explained by the more timely, albeit small, increase in anti-inflammatory and bronchodilator dose as soon as symptoms worsen. This regimen reduces the risk of adverse effects, but is not suitable for patients who habitually overuse short-acting beta2 agonists, who poorly perceive airway obstruction, or who would be confused by a regimen change.
If further step-up treatment is required, moderate or high-dose combination therapy can be used, but long-term adverse effects should be considered. A few patients remain uncontrolled and should be referred for consideration of other add-on therapy.
Once symptoms are stable for three months and exacerbations are infrequent, step-down should be actively initiated in order to minimise the risk of adverse effects, such as osteoporosis and cataract. Clinicians may be concerned about destabilising previously well patients, but this may result in over-prescribing, and reinforce patient concerns about high doses. It is helpful to explain that both the overall dose and risk of exacerbations can be lowered by gradually decreasing to a low, regular, daily dose, rather than by stopping and starting treatment.
Maintenance treatment can be gradually reduced at intervals of around two months, with inhaled corticosteroid dose reduced by 25–50% each time. Each change should be treated as a therapeutic trial, with the level of asthma control documented. There are few studies on which to base recommendations, but it would be reasonable to check lung function after the dose of inhaled corticosteroid has been reduced by 50%, or more frequently for patients who are anxious or at greater risk. Patients should be advised to return to the previous dose or medication and contact the doctor if their asthma is consistently worse after a step-down.
For patients taking conventional fixed-dose combination therapy, step down through the available formulations. This reduces the inhaled corticosteroid dose by around 50% each time, mostly without changing the dose of long-acting beta2 agonist. For patients taking the budesonide/eformoterol combination as maintenance and reliever therapy, the maintenance dose can be reduced, with the as-needed doses providing an immediate safety net if the patient’s control deteriorates.
Once the lowest dose of combination therapy has been reached, options are to shift to once-daily dosing, which can be an effective option when the inhaled corticosteroid dose is ≤400 microgram daily, or to withdraw the long-acting beta2 agonist and treat with inhaled corticosteroid alone.13
Stepping-up and stepping-down treatment for asthma is not substantially different from the treatment principles for hypertension or diabetes. Assess the patient’s status, prescribe an appropriate starting medication, ensure that the patient knows how and when to take it, review the patient’s response, then monitor and readjust the treatment over subsequent visits. Inhaler technique and adherence should be assessed at every visit.
Associate Professor Reddel has served on advisory boards for AstraZeneca, GlaxoSmithKline and Novartis, has provided consulting for Biota, GlaxoSmithKline and Novartis. She has received honoraria from AstraZeneca, Boehringer Ingelheim and GlaxoSmithKline for educational presentations, is chairing a joint data monitoring committee for AstraZeneca, GlaxoSmithKline, Merck and Novartis, and has received research funding from AstraZeneca and GlaxoSmithKline.
Note: The June issue will feature an article on written asthma plans.
The following statements are either true or false.
1. The severity of a patient’s asthma is determined by their symptoms and lung function at the time of diagnosis.
2. Patients with newly diagnosed asthma should start treatment with a combination inhaler containing a corticosteroid and a long-acting beta2 agonist.
Answers to self-help questions1. False
Chair of the GINA Science Committee (Global Initiative for Asthma)
Clinical associate professor, University of Sydney
Respiratory physician, Royal Prince Alfred Hospital, Sydney
Research leader, Woolcock Institute of Medical Research