Long-acting beta(2) agonists in the management of stable chronic obstructive pulmonary disease

Long-acting beta(2) agonist bronchodilators (e.g. formoterol, salmeterol) a re a new interesting therapeutic option for patients with chronic obstructi ve pulmonary disease (COPD). In the short term, both salmeterol and formoterol appear to be more effecti ve than short-acting beta(2) agonists, and in patients with stable COPD the y are more effective than anticholinergic agents and theophylline. Regular treatment of patients with COPD with long-acting beta(2) agonists c an 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 beta(2) agonist and an anticholinergic agent or theophylline in patients with COPD has not been su fficiently studied. Combination of usual doses of ipratropium or oxitropium with usual doses of salmeterol or formoterol does not appear to improve pu lmonary function, but this lack of improvement with the combination should not, in itself, prevent implementation of further therapeutic steps in pati ents 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. Ho wever adverse cardiac events might occur in patients with COPD with pre-exi sting cardiac arrhythmias and hypoxaemia if they use long-acting beta(2) ag onists, although the recommended single dose of salmeterol 50 mu g or formo terol 12 mu g ensures a relatively higher safety margin than formoterol 24 mu g. The bronchodilatory effect of long-acting beta(2) agonists seems to be fair ly stable after regular treatment with these bronchodilators. Moreover, pre -treatment with a conventional dose of formoterol or salmeterol does not pr eclude the possibility of inducing further bronchodilation with salbutamol in patients with partially reversible COPD. All these findings support the use of long-acting beta(2) agonist bronchodi lators as first-line bronchodilator therapy for the long term treatment of airflow obstruction in patients with COPD. However, since physicians must a lways choose a drug that is highly efficacious, well tolerated and inexpens ive, the cost-effectiveness analysis in relation to Ether bronchodilators w ill determine the proper place of long-acting beta(2) agonists in the long term therapy of stable COPD.