Current therapies for asthma. Promise and limitations.

Effective treatments for asthma exist, but morbidity and mortality have continued to climb. Many attempts have been made to refine rather than change therapy over the past 20 years. Drugs currently used to treat asthma include beta 2-agonists, glucocorticoids, theophylline, cromones, and anticholinergic agents. For acute, severe asthma, the inhaled beta 2-agonists are the most effective bronchodilators. Short-acting forms give rapid relief; long-acting agents provide sustained relief and help nocturnal asthma; and serious adverse effects are rare when these drugs are used properly. First-line therapy for chronic asthma is inhaled glucocorticoids, the only currently available agents that reduce airway inflammation. Their side effects can be reduced by rinsing the mouth or by using large-volume spacers. Theophylline is a bronchodilator that is useful for severe and nocturnal asthma, but recent studies suggest that it may also have an immunomodulatory effect. Although theophylline is inexpensive, monitoring its plasma concentrations is both expensive and inconvenient. Cromones work best for patients who have mild asthma: they have few adverse effects, but their activity is brief, so they must be given four times daily. The anticholinergic bronchodilators are more useful for treating COPD than for chronic asthma. These drugs have virtually no side effects, and their onset is slower and their action longer than inhaled beta 2-agonists. The new direction in treating asthma will be orally administered medication that has few side effects and is targeted specifically to the pathogenesis of asthma.