PURPOSE:A rapid onset of action from their bronchodilator may be important for chronic obstructive pulmonary disease (COPD) patients with nocturnal or early morning symptoms. We report findings from a study designed to compare the efficacy of formoterol with salmeterol five minutes after dose administration.
METHODS:This was a 28-day, randomized, multicenter, open-label, parallel-group study of formoterol 12 μg administered twice-daily (BID) vs salmeterol 50 μg BID in 270 COPD patients aged ≥40 years who were current or previous smokers. The primary variable was the effect of each drug on forced expiratory volume in 1 second (FEV1) 5 minutes after inhalation. Secondary endpoints included changes from baseline in FEV1 at 30 and 60 minutes postdose, the 6-min Walk Test (6MWT), as well as rescue medication use. Analysis of covariance (for FEV1 changes and 6MWT) or analysis of variance (for rescue medication use) was used to calculate least square means and P values.
RESULTS:At day 28, 5 minutes after drug administration (the first scheduled measurement), patients receiving formoterol experienced a mean change from baseline of 0.13 L in FEV1 compared to a 0.07-L mean change in patients receiving salmeterol (P=0.022). After 30 minutes postdose, patients receiving formoterol experienced a mean change of 0.17 L compared to only 0.07 L for patients receiving salmeterol (P<0.001). A similar change was reported at 60 minutes postdose (0.19 L for the formoterol group vs 0.13 L for the salmeterol group; P=0.069). Patients on formoterol also reported fewer instances of rescue medication use and longer 6MWT distances than patients on salmeterol, however, these numerical differences did not reach statistical significance.
CONCLUSION:The onset of action of formoterol (FEV1) was significantly faster than salmeterol with differences reaching statistical significance as early as 5 minutes postdose, the earliest scheduled measurement. No significant differences in AEs between drugs were observed.
CLINICAL IMPLICATIONS:The faster onset of action of formoterol may improve user compliance with treatment in real-life conditions.
DISCLOSURE:Claudia Cote, Consultant fee, speaker bureau, advisory committee, etc. Dr. Cote has served as a consultant and has participated in speaker's bureaus for Boehringer-Ingelheim, Pfizer, Dey Pharmaceutical, and GlaxoSmithKline.; No Product/Research Disclosure Information