Asthma therapy: present trends and future prospects

The short-term treatment of asthma has for years included supplemental oxygen, IV theophylline, and subcutaneously administered and inhaled beta-adrenergic agonists, anticholinergics, and corticosteroids. This regimen has not really changed. What have changed, however, are the specificity of the drugs and the mode of their administration. Metered-dose inhalers can deliver selective beta-adrenergic agonists, anticholinergics, and corticosteroids directly to the airway mucosa. Topical delivery of medication has dramatically reduced the side effects of all classes of medication. As experience accrues, more studies indicate that inhalation therapy may become the mainstay of asthma treatment, even in the emergency department. Metered-dose inhalers have also aided in the resurgence of the use of cromolyn. There is certainly improved ease of administration and perhaps a reduced incidence of rebound bronchospasm. The appearance of newer beta 2-adrenergic agonists with improved beta 2-adrenergic selectivity and longer half-lives underscores the activity in asthma research. There is hope that selective bronchodilating corticosteroids or calcium-channel blockers can be developed. Bronchodilating prostaglandins and leukotrienes, or inhibitors of prostaglandins and leukotrienes that cause bronchoconstriction, are being investigated. An oral mast-cell membrane stabilizer is available and hopefully can be improved. Finally, the transdermal delivery of medication may open an entirely new avenue for the treatment of those suffering from asthma.