Long-acting beta2 agonist
bronchodilators (e.g.
formoterol,
salmeterol) are a new interesting therapeutic option for patients with
chronic obstructive pulmonary disease (
COPD). In the short term, both
salmeterol and
formoterol appear to be more effective than short-acting beta2 agonists, and in patients with stable
COPD they are more effective than
anticholinergic agents and
theophylline. Regular treatment of patients with
COPD with long-acting beta2 agonists can induce an improvement in the respiratory function and certain aspects of quality of life. Moreover,
salmeterol seems to be better than
ipratropium and
theophylline in improving lung function at the recommended doses after a long term treatment. Use of combination
therapy of a long-acting inhaled beta2 agonist and an
anticholinergic agent or
theophylline in patients with
COPD has not been sufficiently studied. Combination of usual doses of
ipratropium or
oxitropium with usual doses of
salmeterol or
formoterol does not appear to improve pulmonary function, but this lack of improvement with the combination should not, in itself, prevent implementation of further therapeutic steps in patients responsive to an
anticholinergic agent and/or
salmeterol or
formoterol administered singly. Neither
formoterol nor
salmeterol elicit significant cardiovascular effects in healthy individuals and patients with reversible
airway obstruction. However,
adverse cardiac events might occur in patients with
COPD with pre-existing
cardiac arrhythmias and hypoxaemia if they use long-acting 12 agonists, although the recommended single dose of
salmeterol 50 microg or
formoterol 12 microg ensures a relatively higher safety margin than
formoterol 24 microg. The bronchodilatory effect of long-acting beta2 agonists seems to be fairly stable after regular treatment with these
bronchodilators. Moreover, pre-treatment with a conventional dose of
formoterol or
salmeterol does not preclude the possibility of inducing further bronchodilation with
salbutamol in patients with partially reversible
COPD. All these findings support the use of long-acting beta2 agonist
bronchodilators as first-line
bronchodilator therapy for the long term treatment of airflow obstruction in patients with
COPD. However, since physicians must always choose a
drug that is highly efficacious, well tolerated and inexpensive, the cost-effectiveness analysis in relation to other
bronchodilators will determine the proper place of long-acting beta2 agonists in the long term
therapy of stable
COPD.