Patients with
chronic obstructive pulmonary disease (
COPD) may benefit from long term treatment with
bronchodilators despite having a modest acute response to these drugs. To investigate the efficacy of
salmeterol in smokers with
COPD a double blind, randomised, crossover comparison was performed between
salmeterol (50 micrograms twice daily) and placebo in 63 patients with stable
COPD (mean age 63 yrs); inclusion criteria: aFEV1) < 60% of predicted and FEV1 reversibility < 15% (0.4 mg
salbutamol). Patients received four weeks of
therapy with each of the treatment regimens. Assessment of efficacy was done by recording morning and evening peak expiratory flow rates (PEF), respiratory symptoms, and use of rescue
salbutamol. Morning PEF values were higher during the
salmeterol than during the placebo period, although the mean treatment difference was small (12 l/min (95% confidence limits 6 to 17)). No difference in mean evening PEF values was found. Diurnal variation in PEF was more pronounced during the placebo than during the
salmeterol period. Compared with placebo, treatment with
salmeterol was associated with lower day time and night time symptom scores and less use of rescue
salbutamol both during the day and the night. This study shows that, compared with placebo, treatment with
salmeterol produces an improvement in respiratory symptoms and morning PEF values in patients with moderate to severe
COPD. Treatment with long acting beta(2)-agonists may therefore result in an improvement in functional status, even in patients suffering from apparently non-reversible
obstructive pulmonary disease.