CHRONIC OBSTRUCTIVE PULMONARY DISEASE Early onset of effect of salmeterol and fluticasone propionate in chronic obstructive pulmonary disease

Background: Combined treatment with inhaled corticosteroids and long acting b2 agonists is approved for the treatment of chronic obstructive pulmonary disease (COPD), but little is known about the onset of effect of the combination. Methods: Data were used from 1465 patients with COPD entered into a large 1 year double blind trial with daily measurements of peak expiratory flow (PEF) and symptom scores. Results: PEF was significantly higher after 1 day in patients treated with salmeterol 50 mg twice daily or the salmeterol/fluticasone propionate combination 50/500 mg twice daily than placebo. In patients treated with fluticasone propionate 500 mg twice daily alone, PEF differed from placebo after 2 days. The differences after 2 weeks compared with placebo were 16 l/min (95% confidence interval (CI) 11 to 21), 11 l/min (95% CI 6 to 16), and 27 l/min (95% CI 22 to 33) for salmeterol, fluticasone propionate, and the salmeterol/fluticasone propionate combination, respectively. For all treatments the effect on PEF after 2 weeks was comparable to that seen at the end of the study. The difference between the salmeterol/ fluticasone propionate combination and placebo after 2 weeks as a percentage of baseline was similar for PEF and clinic forced expiratory volume in 1 second (FEV1). Differences in breathlessness scores were statistically significant after 1 day for the group treated with salmeterol alone and after 2 days for the combination group. The 2 week change in FEV1 was only partly indicative of a long term response in individual patients. Conclusions: The effects of salmeterol and fluticasone propionate, alone or in combination, on PEF and breathlessness are seen within days and most of the obtainable effect on these parameters is reached within 2 weeks.