Written by William Storms, M.D.
Exercise-induced bronchospasm (EIB) is a condition of the bronchial tubes of the lungs that results in airway narrowing (bronchospasm) during or after exercise. It is found in 90 percent of patients with asthma and about 15-20 percent of the general population, many of whom are unaware that they have the condition. The typical symptoms are coughing, wheezing, chest tightness and/or shortness of breath after about eight minutes of exercise. There are some atypical symptoms that can also indicate EIB, such as prolonged coughing after exercise, poor performance, muscle cramps, nausea, or extensive fatigue with exercise.
Do I have to have asthma or allergies to have EIB?
No, many otherwise-normal individuals have EIB. There have been multiple surveys of school children, college athletes, and the general public showing that up to 15-30 percent of these groups have EIB, and one-third to one-half do not know they have it. Surveys done on Olympic athletes have shown that approximately 17 percent have EIB; many of whom were unaware of the condition until they were tested.
What tests are done to show that a person has EIB?
The most accurate test is a spirometry (hand-held electronic device measuring lung function) performed before and after the specific exercise the subject is doing. Since many doctors do not have spirometers in their office, this is not a common test. However, most allergists do have these machines. The test is commonly used by U.S. Olympic Committee sports physiologists to screen athletes for EIB.
Another test that can be done is a peak flow rate, which can be done with an inexpensive hand-held device, to measure the peak expiratory flow rate of the lungs before and after exercise. However, this is not as accurate as a spirometer. In case there is no spirometer or peak flow meter available, the physician may prescribe a treatment (inhaler) for EIB. If that treatment is effective, it usually confirms the diagnosis.
What are the treatments for EIB?
There are two forms of treatment: Nonpharmacological therapy and pharmacological therapy.
This involves having the athlete warm-up to approximately 80 percent of their maximum heart rate before exercise or competition. Another way to accomplish this is to start the exercise very slowly and make sure that the first eight minutes are a slow warm-up; this will help partially prevent the EIB. This type of warm-up reduces EIB but does not totally prevent it.
There are many forms of pharmacologic therapy, and the therapy used really depends on the individual. Some individuals respond well to one therapy and others to a different therapy.
- Albuterol. Most physicians will prescribe an inhaler called albuterol to be taken shortly before exercise. This is quite effective but can cause some increased heart rate and jitteriness.
- Cromolyn. The other inhaler that is specific for EIB is cromolyn, and it is recommended that at least four puffs be taken just prior to exercise. This inhaler does not have the side effects of albuterol.
- Montelukast. This is an anti-allergy/antiasthma pill which is taken daily to control allergies and asthma. It is effective for many people with EIB if taken daily.
- Salmeterol and Formoterol. These are beta-agonist inhalers which are similar to albuterol but are much longer-acting, up to 12 hours. These can be taken prior to exercise (1-1/2 hours prior for salmeterol and 10 minutes prior for formoterol), with good protection against EIB. When taken every day, there may be some loss of effect with these medications in some people and if this happens then they should not be taken on a daily basis.
- Inhaled steroids. There are many inhaled steroids on the market (QVAR, Asmanex, Azmacort, Flovent, Pulmicort, etc.). These are inhaled products which are given once or twice every day. They take about two weeks to work for EIB and must be continued indefinitely.
Each person is potentially different in their response to medications; most people have a good response with cromolyn and/or albuterol. Some people respond very well to montelukast. These would be the first-line drugs that would be recommended. If these are not totally effective, then daily inhaled steroids are the next step. At this point it would be very important to have the patient be evaluated by a specialist, either a board-certified allergist or a board-certified pulmonologist, since the EIB diagnosis should be reconsidered.
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