Effects of formoterol in apparently poorly reversible chronic obstructive pulmonary disease

This randomized, double-blind, placebo-controlled, crossover study was desi gned to investigate the effects of the long-acting beta(2)-adrenoreceptor a gonist formoterol fumarate in 12 current or exsmokers having chronic obstru ctive pulmonary disease, with a mean forced expiratory volume in one second (FEV1) 47% of predicted, poorly reversible (5.1% pred) after terbutaline s ulphate inhalation. After inhaling a single dose of formoterol (6 or 24 mu g), or placebo via T urbuhaler(R) FEV1 and pulmonary function parameters measured during quiet b reathing (work of breathing (WoB) and airway resistance (Raw)) were recorde d over 12 h on three test days. Immediate changes in FEV1 were modest, although each dose of formoterol cau sed a response >12% pred within 10 min in one subject. Compared to placebo, both doses of formoterol induced a clinically and statistically relevant i mprovement in WoB (>25%) and Raw (>20%), which occurred within 10 min and t asted over a period of 12 h (p less than or equal to 0.02, analysis of vari ance). Thus, inhaled formoterol causes long-lasting lung functional improvements i n apparently poorly reversible chronic obstructive pulmonary disease. Addit ional lung function measurements during quiet breathing after forced expira tion tests may be useful in such patients to assess beneficial effects of b ronchodilators.