B2-Adrenergic Agonists
The B2-adrenergic agonists are effective in preventing exercise-induced asthma. If a short-acting agent is given ten to fifteen minutes before exertion the immediate bronchoconstriction may be completely blocked. The long-acting B2-agonists such as
salmeterol may be particularly helpful since their lengthy duration may also block the late phase attack. Remember, however, that long-acting B-agonists take longer to become effective so should be given thirty to forty-five minutes before exercise begins.
B-Agonists for Children
In young children a metered-dose inhaler (MDI) may be difficult to use, so a spacer with or without a face mask may improve medication. Some children, particularly those younger than age five, may benefit more from a nebulizer that administers the B-agonist. Another alternative for young children is the oral syrup form of B-agonist taken at least sixty minutes before exercising.
Anti-Leukotrienes
Leukotrienes have been shown to playa central role in exercise-induced asthma. An anti-leukotriene agent (zafirlukast, montelukast, zileuton) may be added to the treatment of exercise-induced asthma when the B2-adrenergic agonists are not completely effective. It should be noted that these agents are taken orally and must be maintained on a regular basis
to be effective. Patients who are maintained on anti-leukotriene agents should continue to use their B2-adrenergic agonist prior to exercise.
Cromolyn Sodium and Nedocromil Sodium
Cromolyn sodium and nedocromil sodium can also prevent exercise-induced asthma and are an alternative to the B-agonists. In patients with moderate or severe asthma both groups of agents may be used together. Cromolyn and nedocromil can also block the late phase of exercise-induced asthma, but their onset of action may be even slower than the short-acting B-agonists. One study comparing cromolyn and albuterol to prevent exercise-induced asthma found albuterol more effective.
Theophylline
Theophylline can also prevent exercise-induced asthma but is clearly less effective than the B-agonists, cromolyn, and nedocromil. Inhaled corticosteroids cannot prevent the immediate effects of exercise but their use in asthma maintenance therapy would help prevent late phase reactions.
Approved Medications
The NCAA and the International Olympic Committee maintain lists of acceptable medications for athletes. Medications approved by the United States Olympic Committee include B-agonists (aerosol forms only), albuterol, and terbutaline, as well as cromolyn sodium, nedocromil sodium, theophylline, and inhaled corticosteroids.