The Salmeterol Multicenter Asthma Research Trial (SMART)1 reinforces important lessons regarding the appropriate use of long-acting β-agonists. The trial was stopped early because of increased hazard of asthma, respiratory death or life-threatening events in the salmeterol arm. Eric Wooltorton's Health and Drug Alert2 based on data from this study warns physicians of this hazard but fails to put the results in the context of the greater body of research examining the role of long-acting β-agonists in asthma.
Studies examining the use of these drugs in combination with inhaled corticosteroids have consistently demonstrated benefit, with significant reductions in severe asthma exacerbations.3–6 Furthermore, the SMART trial failed to show a significant hazard in patients using inhaled corticosteroids at baseline. Despite this, Wooltorton discounts the role of inhaled corticosteroids as a determinant of outcome, stating “Although there is interest in attributing differences in outcomes to differences in baseline rates of inhaled corticosteroid use at enrolment, the trials were not adequately designed to assess this.”
Although this statement is true, the message is not. The Canadian asthma consensus guidelines,7 in agreement with recommendations worldwide, emphasize the need for adequate anti-inflammatory therapy before starting add-on treatment, including long- acting β-agonists. This was not the case in the SMART trial.
Administration of long-acting β-agonists in combination with inhaled corticosteroids, preferably in a single inhalation device, remains the most effective strategy for prevention of severe asthma exacerbations in those with persistent disease. If we are to reduce asthma morbidity and mortality, it is critical for this message to be understood by clinicians and not confused by reports of inappropriate use.
Footnotes
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Competing interests: Alan Bell has received honoraria and research grants from and has been involved in advisory boards with the following companies: Abbott, Altana, Astra-Zeneca, Bristol-Myers Squibb, GlaxoSmithKline, Novartis, Pfizer and Sanofi-Aventis. Andrew McIvor has received honoraria and research grants and has been involved in advisory boards with the following companies: Abbott, Altana, Astra-Zeneca, Boehringer-Ingelheim, Bayer, Bristol-Myers Squibb, GlaxoSmithKline, Novartis, Pfizer and Sanofi-Aventis.