Résumé
BACKGROUND: Short-acting anticholinergic bronchodilator, ipratropium bromide has been recommended as first-line drug in chronic obstructive pulmonary disease (COPD). More recently, long acting beta2-agonist (LABA) bronchodilators such as formoterol have been shown to be useful in COPD. Limited information is available on the relative efficacy of these two drugs in COPD. METHODOLOGY: A randomised, double-blind, cross-over, placebo-controlled study was carried out. Forty-four stable patients with COPD received single doses of formoterol (12 microg), ipratropium bromide (40 microg) or placebo, administered through a metered-dose inhaler on three consecutive days in a random order. Spirometry, static lung volumes, pulse rate and blood pressure, and assessment of sensation of dyspnoea at rest using a visual analog scale (Borg Scale) were recorded at baseline. Subsequently, these were repeated for assessment of response: spirometry at 5, 30 and 60 minutes and static lung volumes, pulse rate, blood pressure and dyspnoea measurement at 60 minute. RESULTS: Formoterol resulted in greater immediate improvement in lung function, with the change in FEV1 at 5 min being greater than that observed with ipratropium. The changes in static lung volumes were similar between the two but superior to placebo. Both the drugs reduced dyspnoea. Formoterol produced a significantly greater increase in heart rate and systolic blood pressure as compared to ipratropium, although the magnitude of these changes was small and clinically unimportant. CONCLUSIONS: Single therapeutic doses of formoterol and ipratropium bromide are equally effective in improving lung function and reducing dyspnoea. However, formoterol appears to be a better bronchodilator producing a faster improvement in lung function.