Securing the Benefits of Medical Innovation for Seniors: The Role of Prescription Drugs and Drug Coverage. Asthma

07/01/2002

  • In 1999, 26.7 million people in the U.S. reported that they had been diagnosed with asthma sometime in their lives, and 10.5 million had experienced an asthma attack or episode in the previous 12 months. (CDC 2002)
  • 7.6 percent of seniors report having asthma. (CDC 2002)
  • In 1999, there were 11 million visits for asthma to private physician offices and outpatient departments, 2 million visits to the emergency department, and about one-half million hospitalizations. (CDC 2002)
  • In 1999, 4,657 people died from asthma, at a rate of 1.7 per 100,000 population. (CDC 2002)

Asthma is a chronic respiratory disease involving episodes or attacks of small airway narrowing from inflammation and hyper-responsiveness to asthma “triggers.” Triggers may include allergens, infections, exercise, abrupt changes in the weather, and exposure to environmental irritants such as cigarette smoke. Asthma attacks can vary from mild to life threatening, and involve shortness of breath, coughing, wheezing, chest pain or tightness, or a combination of these symptoms. Asthma has become more common over the past two decades, and it remains a key public health problem in the United States. (MMWR 2002)

Treatment of asthma

In addition to avoiding triggers, treatment of asthma usually consists of some combination of bronchodilators and anti-inflammatory agents. Bronchodilators work to relax the muscles in airway walls, opening breathing passages. Anti-inflammatory drugs work to reduce swelling, inflammation, and mucous in airways thereby relieving some of the obstruction to airflow. Corticosteroids are one common class of anti-inflammatory drugs used in treating asthma. Although effective, long-term treatment with corticosteroids, particularly when taken by pill, may have significant side effects, such as bone mineral loss, weight gain, and stomach irritation. A few nonsteroidal pharmaceuticals to reduce airway inflammation are currently available. These agents do not have the side effects that corticosteroids may produce. (Gawchik 2000)

Recently introduced leukotriene antagonists represent the first truly new approach in treating asthma in the past 30 years. Montelukast, a leukotriene receptor antagonist, is the first in this class that targets a specific receptor for a substance that is involved in the inflammatory response in the airways. Since this drug inhibits the inflammatory response, it is indicated for prophylaxis to reduce asthma attacks. Use of montelukast may eliminate or decrease the need for chronic use of inhaled corticosteroids, which can have significant side effects and which are difficult for some patients to use effectively. (Lipworth 1999)

Montelukast (Singulair®) is approved in the U.S. for the prophylaxis and chronic treatment of asthma. New Zealand, Australia, Belgium and Finland do not currently provide coverage for this medication. In addition, many provinces in Canada restrict coverage of montelukast only to patients who are not able to control their asthma symptoms with inhaled corticosteroids. (Quebec Prescription Drug Insurance Plan)

Drugs in the pipeline for asthma

  • Novel agents for the treatment of asthma that target different parts of the inflammatory cascade are in clinical development. These include compounds that target cells, antibodies, cell receptors, mediators, and cell signaling substances. (Hansel 2001)
  • Preliminary studies of selective enzyme inhibitors have shown promise. (Szelenyi 2002)
  • New glucocorticoids with less severe side effects are being developed. (Szelenyi 2002)

Numerous agents that attack different parts of the inflammatory response seen in asthma are in clinical development. (Crystal 2001, PhRMA 2002) By disrupting the inflammatory cascade and reducing airway inflammation, asthma may be better controlled and acute attacks prevented. These compounds target specific cells, antibodies, inflammatory mediators, cell surface proteins, and cell signaling substances that are involved in producing an acute asthma attack. (Hansel 2001) In addition, there are efforts to produce new corticosteroids that have significantly fewer side effects. (Szelenyi 2002) PhRMA reports that twenty-seven medications are currently in clinical trials for the treatment of asthma. (PhRMA 2002)

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