Drugs Used in Asthma: Treatment Strategy

TREATMENT STRATEGY

Clinical symptoms alone cannot be used as an accurate assessment of the severity of physiological impairment in the asthmatic patient, because a substantial degree of impairment may persist even after symptoms are re-lieved by treatment. Consequently, the overall objec-tives of antiasthma therapy are to return lung function to as near normal as possible and to prevent acute ex-acerbations of the disease. For quality of life, the ideal regimen permits normal activities, including exercise, with minimal or no side effects.

The primary classes of drugs used to treat asthma are bronchodilators and antiinflammatory agents. Broncho-dilators include theophylline, a variety of adreno-mimetic amines, and ipratropium bromide. Antiinflam-matory therapy consists of the corticosteroids. A growing collection of drugs called alternative therapies cannot be classified clearly as either bronchodilators or antiinflammatory agents. These agents include the leukotriene modulators, cromolyn sodium, and ne-docromil sodium.

Bronchodilators are used both in maintenance ther-apy and as needed to reverse acute attacks. These agents are often referred to as relievers because they provide rapid symptomatic relief but do not affect the funda-mental disease process. Based on the underlying patho-physiology of the disease, antiinflammatory therapy must be used in conjunction with bronchodilators in all but the mildest asthmatics. Antiinflammatory agents are also called controllers because they provide long-term stabilization of symptoms. In addition to drug therapy, all treatment regimens should include patient education focused on three key behaviors: (1) the appropriate use of medications to control symptoms (e.g., proper tech-nique for use of metered-dose inhalers), (2) recognition of the signs of a deteriorating disease status (e.g., a progressive increase in the use of bronchodilators), and (3) prevention strategies (e.g., avoidance of anti-genic material; influenza vaccination to forestall virus-induced exacerbations).

Pharmacotherapy of asthma is managed in a step-wise fashion according to the severity of the disease. Recommendations for the stepwise treatment of asthma in adults and children older than 5 years of age are shown in Table 39.1.