Currently in the USA there are three leukotriene inhibitors approved by the Food and Drug Administration. Several other leukotriene inhibitor drugs are in the process of clinical trials. The relative advantages and best doses of these medications are not yet known well. Since these drugs are so new, it is possible that rare side effects will be discovered only after the drugs have been used more extensively. Avoiding exercise can be a real problem, since it appears that regular exercise builds up resistance to asthma symptoms.
Exercise can also help clear mucus from the lungs.
Although exercise will lead to some wheezing, the overall level of wheezing seems to go down, and the likelihood of wheezing at periods such as the middle of the night or an allergic reaction to food may be reduced. This built up resistance can reduce some of the more inconvenient and dangerous effects of asthma. These drugs are similar in their actions to epinephrine, a signaling molecule that the body uses in emergencies that opens up breathing passages. Using these epinephrine-like drugs, usually as inhaler sprays, opens clogged breathing passages in the lungs. This reduces wheezing in the short run very effectively, and appears to reduce the base rate of wheezing in most people.