From adrenaline to formoterol: advances in beta-agonist therapy in the treatment of asthma.

Long-acting beta2-agonists (formoterol and salmeterol) represent the latest advance in a series of improvements in beta-agonist asthma therapy since the introduction of isoprenaline. Traditional inhaled short-acting beta2-agonists (salbutamol and terbutaline) provide rapid as-needed symptom relief and short-term prophylactic protection against bronchoconstriction induced by exercise or other stimuli. Where symptoms are not adequately controlled by corticosteroids alone, inhaled selective long-acting beta2-agonists are used additionally for maintenance. Salmeterol and formoterol are well tolerated, provide effective long-term symptom control and reduce the incidence of exacerbations; any development of tolerance or masking of underlying inflammation with continual use does not appear to be clinically relevant. Formoterol is both rapid acting (as fast as salbutamol) and long acting (similar to salmeterol). Increasing clinical evidence suggests that inhaled formoterol is a convenient and well-tolerated treatment that is effective both for regular maintenance and as-needed relief of symptoms.