Asthma: 2. Trends in pharmacologic therapy.

The most reasonable first therapy for ambulatory asthmatic patients is regular use of a selective beta 2-adrenoreceptor agonist administered with a metered-dose inhaler. When asthma is of more than mild severity, a second agent that acts through a different pharmacologic pathway is added. Although theophylline has traditionally been this second agent, recent concerns about its safety have prompted increasing use of inhalational agents such as corticosteroids, anticholinergics and mast cell stabilizers as appropriate second-line therapy. The use of such combination regimens and newer strategies such as high-dose inhaled corticosteroid therapy will reduce the proportion of patients who require systemic corticosteroid therapy for adequate control of asthma. The use of combination inhalational therapy also has a role in the management of asthma in the emergency department, the combination of a nebulized adrenoreceptor agonist and a nebulized anticholinergic being more effective than either agent alone in acute, severe asthma. The role of newer xanthine derivatives, antihistamines, calcium channel blockers and selective anti-inflammatory agents remains investigational.