MONTELUKAST VERSUS SALMETEROL IN PATIENTS WITH ASTHMA AND EXERCISE-INDUCED BRONCHOCONSTRICTION

Villaran C, O'Neill SJ, Heibling A, et al. J Allergy Clin Immunol. 1999;104:547-553 ROBERT A. WOOD, MD Baltimore, [...]
Purpose of the Study. Both montelukast, a leukotriene receptor antagonist, and salmeterol, a long-acting [Β.sub.2]-agonist, have been show to protect against exercise-induced bronchoconstriction (EIB) in short-term studies. This study was designed to compare these 2 agents in a longer term fashion for the treatment of EIB. Study Population. One hundred ninety-seven patients between the ages of 14 and 45 years with mild asthma and a positive response to an exercise challenge, defined as a postexercise decrease in forced expiratory volume in 1 second ([FEV.sub.1]) of at least 18%. Methods. Patients were randomized in a double-blind protocol to receive either montelukast 10 mg once-daily or salmeterol 50 µg twice-daily for 8 weeks. Exercise challenges were repeated at day 3 and weeks 4 and 8. The primary efficacy endpoint was the maximal percent decrease in postexercise [FEV.sub.1] at week 8. Results. The 2 drugs provided similar protection at day 3 but thereafter montelukast was superior. For example, at week 8 the maximal fall in [FEV.sub.1] after exercise was 15.9% for montelukast and 20.2% for salmeterol (P [is less than] .001), compared with 33.1% and 30.9% at baseline. In addition, clinical adverse events were significantly less common in the montelukast group. Conclusions. Montelukast was more effective than salmeterol in the chronic treatment of EIB over an 8-week period in patients with mild asthma. Montelukast may be a better alternative than salmeterol for the chronic treatment of EIB, especially in view of the lower rate of adverse events. Reviewer's Comments. For many years [Β.sub.2]-agonists have been considered the gold standard for the prevention of exercise-induced asthma. Although this should not be considered the final answer for all patients (and a similar study in children is absolutely necessary), the results of this comparative trial appear very significant. The control of EIB should be a goal for every child with asthma and the leukotriene antagonists may play an important role in achieving that goal. In addition, it is important to note that the most likely reason that the drugs were comparable at day 3 but different by week 4 is that patients may develop a tolerance to the effects of salmeterol with long-term use. This has been demonstrated in several previous studies and although there has been debate as to how clinically significant this may be, it certainly may be relevant to at least some of your patients.