For Patients with Asthma Symptoms during Exercise: Singulair (Montelukast Sodium) Approved
Symptoms of exercise-induced asthma include wheezing, tightness or pain in the chest, coughing, and in some cases, prolonged shortness of breath. Some symptoms are more noticeable than others, which means exercise-induced asthma can sometimes go undiagnosed.Children with exercise-induced asthma often begin experiencing symptoms 5 to 10 minutes after they start exercising.Up to 90% of kids with asthma have symptoms when they exercise.
Exercise-induced bronchoconstriction is common among adults with mild-to-severe asthma, limiting activity and worsening the quality of life. The presence of airway hyperresponsiveness to exercise suggests a lack of control of asthma. Accordingly, the degree of protection afforded by a drug against exercise-induced bronchoconstriction may be used to assess therapeutic benefit in patients with mild asthma who have near-normal airway function and minimal symptoms.
Bronchial hyper-responsiveness [breathlessness, fatigue, chest pain, etc] to various stimuli, including exercise, is the most specific sign of asthma. Typically exercise-induced asthma [EIA] consists of coughing, wheezing, chest tightness, chest pain or any combination of these symptoms during exercise, or more so, about eight to 15 minutes after exercise.Adequate control of asthma may increase exercise capacity. This is importrant for maintaining both general and respiratory fitness.
Exercise-induced asthma is not a distinct type of asthma. Instead, it is likely to occur in anyone who has the airway reactivity that underlies asthma. Your airways — the passages branching off your windpipe to carry air to and from your lungs — are reactive if they tend to narrow under certain circumstances, such as after exposure to an allergen or while you are suffering from a cold. The linings of reactive airways are prone to inflammation and excess mucus secretion as well.
The cause of exercise-induced bronchoconstriction is incompletely understood, although airway cooling and drying are hypothesized to stimulate the release of inflammatory mediators such as the cysteinyl leukotrienes (leukotriene C4, D4, and E4),1 which are excreted in urine as leukotriene E4 (a stable metabolite of leukotriene C4 and D4) after exercise challenge. Inhibitors of the synthesis of leukotriene4, and leukotriene-receptor antagonists have been shown to protect against exercise-induced bronchoconstriction.
People with mild exercise-induced asthma may not realize that their symptoms go beyond the body's normal response to exertion. They blame their difficulty on being out of shape or short on endurance. The good news is that when your asthma is properly recognized and treated, you'll probably be able to exercise as much as you want.
Asthmatic children should be helped to participate in sports and physical activities. Pre-medication shortly before physical activity or training and prophylactic treatment should be considered in management of exerciseinduced asthma.
Exercise-induced asthma can be successfully treated with medicine. The kind of medicine usually tried first is an inhaled bronchodilator. Examples of these medicines are albuterol and pirbuterol. Your health care provider will instruct you to take 2 puffs of this medicine about 15 to 30 minutes before your activity. If your provider tells you to, you may also use this medicine during your activity if you get symptoms.
Other medicines that may be tried include cromolyn or nedocromil.Long-acting beta2-agonists are used for preventing an asthma attack (not for treating attack symptoms). The effects of one dose of a long-acting beta2-agonist last for about 12 hours, so they are particularly effective during the night. These drugs also may be used for prevention of exercise-induced asthma in people and to protect against aspirin-induced asthma.However, research indicates that long-acting beta2-agonists can worsen asthma by increasing symptom severity. These drugs may also increase the risk for asthma-related deaths.
Montelukast is a potent, specific antagonist of leukotriene receptors that was recently approved in the United States and other countries for the treatment of chronic asthma. The protective effects of two doses of montelukast on exercise-induced bronchoconstriction have been shown at 20 to 24 hours after dosing. In a 12-week, placebo-controlled study, we evaluated the effect of once-daily montelukast on airway hyperresponsiveness to exercise and methacholine challenges and on the overall clinical condition of patients with mild asthma.
The U.S. Food and Drug Administration has approved the Merck asthma and allergy drug Singulair (montelukast sodium) for people aged 15 and older who experience asthma symptoms during exercise, the company said Wednesday.
Symptoms of the condition, medically known as exercise-induced bronchoconstriction, include shortness of breath, coughing, wheezing and chest tightness.
In clinical testing involving 160 people, those who took a 10-milligram dose of Singulair two hours before exercise showed a significant reduction in symptoms compared with those who took a placebo, Merck said in a statement.
People who already take Singulair daily for other reasons, including chronic asthma, should never take an additional dose before exercise, the company warned.
Side effects reported during clinical testing included headache, ear infection, sore throat and upper respiratory infection.
Singulair is already approved to treat asthma in people 1 year and older, and for seasonal allergy symptoms in adults and children 2 years and older.