A Comparison of Two Drugs to Treat Exercise-Induced Asthma FREE

In some people, exercise triggers narrowing of the airways (bronchoconstriction), a form of asthma. Previous studies have shown that a relatively new drug, montelukast, protects against exercise-induced asthma. However, it is not known whether montelukast works better than some of the older asthma drugs, such as salmeterol. Montelukast is taken by mouth in the form of a pill once a day. Salmeterol is inhaled from a special spray container twice a day.

The researchers wanted to compare directly the effectiveness of daily montelukast with that of daily salmeterol in preventing asthma triggered by exercise.

One hundred ninety one adults with asthma who were known to have exercise-induced asthma.

The researchers randomly assigned patients either to swallow one montelukast pill in the evening or to inhale two puffs of salmeterol two times a day. To prevent both study patients and the doctors caring for them from knowing which treatment patients were getting, those receiving montelukast also inhaled two puffs of an inactive substance (placebo) two times daily and those getting salmeterol took one inactive pill (placebo) each evening. These treatments continued for 8 weeks. During the first 3 days of therapy and after 4 and 8 weeks of therapy, all patients had special breathing tests before and after exercising on a treadmill.

After 3 days of treatment, patients in the montelukast and salmeterol groups showed similar protection against exercise-induced asthma. However, by 4 weeks, the benefit of salmeterol was less than that of montelukast. By week 8, 67% of the patients on montelukast did not experience significant deterioration in breathing after exercise, while only 46% of the patients on salmeterol did not experience deterioration in breathing.

First, neither montelukast nor salmeterol provided complete protection against asthma associated with exercise. It may therefore be necessary also to treat some patients with shorter-acting drugs immediately before exercise in addition to longer-acting drugs, such as montelukast or salmeterol. Second, the study did not compare the effect of each drug shortly after it was given (that is, at its “peak effect”). Third, the study evaluated breathing in response to exercise in a laboratory setting rather than in patients' real world settings. Fourth, it is not clear whether the benefit of montelukast would continue beyond 8 weeks. Finally, this study had limited ability to detect unwanted side effects from the drugs, although both drugs appear to be relatively safe. Of note, the company that sells montelukast supported this study.

Although both montelukast and salmeterol offer protection against exercise-induced asthma, the protective effect of salmeterol diminished after 4 weeks compared with montelukast. Montelukast may be a more useful first-choice treatment for this condition, although treatment with other agents just before exercise may also be necessary for some patients who are taking montelukast.