Newer Asthma Therapies

• Asthma
• Montelukast
• Becklomethasone
• Forced expiratory volume
• Adrenergic β-agonists

For more than 30 years, the medications available for treating asthma have included β-agonists (such as albuterol), phosphodiesterase inhibitors (such as theophylline), corticosteroids (such as prednisone and beclomethasone), and the so-called antiallergic compounds (such as cromolyn). In the past decade, newer drugs of the same type but with improved characteristics, such as greater specificity and longer duration of action (β₂-agonists) and reduced systemic bioavailability (inhaled corticosteroids) have become available and are widely used. Rigorous clinical trials of these newer preparations have resulted in a better appreciation of their efficacy, potential toxicity, and appropriate use. At the same time, morbidity and mortality caused by asthma have increased (1, 2). Although multiple theories have been proposed to explain this phenomenon, none so far has proven adequate.

As our understanding of the pathophysiology of asthma has improved, new therapeutic targets have been identified, in vitro and animal models have been developed, and new classes of drugs have been synthesized and tested. A wide array of new therapies are now being evaluated in patients with asthma. These include antileukotrienes; platelet activating factor and thromboxane antagonists; antibodies to IgE, CD4, interleukin-4, interleukin-5, and tumor necrosis factor; soluble interleukin-4 receptors; tryptase inhibitors; and NK-2 receptor antagonists. Only one of these new therapies, the antileukotrienes, has been approved for clinical use.

After the identification and characterization of the cysteinyl leukotrienes in the late 1970s (3, 4) and a decade of …