Effects of formoterol on exercise tolerance in severely disabled patients with COPD.
OBJECTIVE
We wished to evaluate the effects of inhaled formoterol, a long-acting beta(2)-adrenergic agonist, on exercise tolerance and dynamic hyperinflation (DH) in severely disabled chronic obstructive pulmonary disease (COPD) patients.


METHODS
In a two-period, crossover study, 21 patients with advanced COPD (FEV(1)=38.8+/-11.7% predicted, 16 patients GOLD stages III-IV) were randomly allocated to receive inhaled formoterol fumarate 12 microg twice daily for 14 days followed by placebo for 14 days, or vice versa. Patients performed constant work-rate cardiopulmonary exercise tests to the limit of tolerance (Tlim) on a cycle ergometer: inspiratory capacity (IC) was obtained at rest and each minute during exercise. Baseline and transitional dyspnoea indices (BDI and TDI) were also recorded.


RESULTS
Eighteen patients completed both treatment periods. Formoterol treatment was associated with an estimated increase of 130 s in Tlim compared with placebo (P=0.052): this corresponded to a 37.8% improvement over placebo (P=0.012). Enhanced exercise tolerance after bronchodilator was associated with diminished DH marked by higher inspiratory reserve and tidal volumes at isotime and exercise cessation (P<0.05). There was no significant difference between formoterol and placebo on exercise dyspnoea ratings; however, all domains of the TDI improved (P<or=0.02) following formoterol, compared with placebo.


CONCLUSIONS
Inhaled formoterol 12 microg twice daily is effective in ameliorating DH, daily dyspnoea and exercise intolerance even in patients with advanced COPD.
Respiratory Division, Department of Medicine, Federal University of Sao Paulo, Rua Professor Francisco de Castro 54, CEP:04020-050, Brazil. albneder@pneumo.epm.br
J Alberto
JA
Neder
Jonathan P
JP
Fuld
Tim
T
Overend
Jackie
J
Thirlwell
Roger
R
Carter
Robin
R
Stevenson
Susan A
SA
Ward
D000280:Administration, Inhalation; D000328:Adult; D000368:Aged; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D006233:Persons with Disabilities / Q000534:rehabilitation*; D004334:Drug Administration Schedule; D016021:Epidemiologic Studies; D004983:Ethanolamines / Q000008:administration & dosage*; D017079:Exercise Tolerance / Q000187:drug effects*; D005260:Female; D000068759:Formoterol Fumarate; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000378:metabolism; D012129:Respiratory Function Tests
D001993:Bronchodilator Agents; D004983:Ethanolamines; D000068759:Formoterol Fumarate