Bronchodilator reversibility to albuterol predicts bronchodilator response to salmeterol.

We read with interest the recent study by Fish et al (August 2001)1 showing that adding salmeterol to inhaled corticosteroid achieved superior control as compared to adding montelukast. However it is likely that the results were biased toward the long-acting 2-agonist as patients were required as an inclusion criteria to have at least 12% increase in FEV1 in response to albuterol. It is therefore perhaps not surprising that for the primary end point of morning peak expiratory flow (PEF), salmeterol exhibited significantly greater bronchodilator efficacy as compared to montelukast. It is also worth noting that both treatments significantly improved the primary outcome variable compared to baseline, and that even allowing for the biased inclusion criteria, there was only a 13 L/min mean difference in morning PEF. One has to question the clinical relevance of this mean difference of 13 L/min, given that the mean baseline value was 370 L/min, and that most PEF meters are calibrated to the nearest 10 L/min. This study provides no information on other relevant clinical efficacy markers, such as protection against bronchoconstrictor stimuli in the presence of increased bronchomotor tone, using bronchial challenge techniques. For example, studies comparing salmeterol and montelukast as add-on therapy have demonstrated greater and more sustained protection against adenosine monophosphate or exercise challenge.2,3 Moreover, the addition of a leukotriene antagonist to concomitant inhaled corticosteroid therapy confers additive anti-inflammatory effects that are not seen with long-acting 2-agonists.