Inhaled adrenergic bronchodilators: Historical development and clinical application

Abstract

The adrenergic bronchodilators that have been developed for oral inhalation represent successive refinement in terms of receptor specificity and duration of action, β agonist bronchodilators have durations of 4-6 hours, or, in the case of salmeterol, of up to 12 hours, offering convenient dosing. Inhalation of the aerosol formulations targets the lung directly. The release of levalbuterol now provides an agent with a single isomer active on β-2 receptors. The currently available agents offer clinicians and patients with reversible obstructive lung disease a choice of sophisticated drugs for airway smooth muscle relaxation. Although improvements in the drugs have reduced adverse effects and β agonists are considered safe, concerns persist about the effect of β agonists in asthma. An improved understanding of asthma pathophysiology may lead to more appropriate use of β agonists in asthma.