Eformoterol n-of-1 trials in chronic obstructive pulmonary disease poorly reversible to salbutamol.
OBJECTIVE
Benefits of long acting beta 2 agonists are unclear for severe chronic obstructive pulmonary disease (COPD) patients with poor response to short acting bronchodilators. We aimed to evaluate 1) effects of eformoterol in such patients using a 'n-of-1' double crossover study design, and 2) aggregate data as a double-blind, double crossover randomized control trial.


METHODS
Subjects with forced expiratory volume in one second (FEV1) < 60% predicted, and poor response to short acting bronchodilators were studied six times over 18 weeks. During that time they were prescribed four weeks of either eformoterol or placebo, followed by the alternate, and then a second crossover. Four-weekly measures included six minute walk distance (6MWD), FEV1, previous two weeks of symptoms, and chronic respiratory questionnaire (CRQ) including treatment goal items.


RESULTS
Of 27 original subjects (21 male, mean age of 70 years, five smokers, mean prebronchodilator FEV1 36% predicted), one subject had clinically significant concordant improvement in the CRQ dyspnoea domain and 6MWD (by 51 metres), but not for other outcomes. There were no concordant improvements in any other subjects. Aggregate double crossover data analysis demonstrated no improvement in any outcome measures.


CONCLUSIONS
The 'n-of-1' study design and aggregate data analysis demonstrated lack of benefit from eformoterol in COPD patients with poor response to short acting bronchodilators.
Smith
B J
BJ
Department of Medicine, University of Adelaide, Australia. Brian.Smith@nwahs.sa.gov.au
Appleton
S L
SL
Veale
A J
AJ
McElroy
H J
HJ
Veljkovic
D
D
Saccoia
L
L
D000318:Adrenergic beta-Agonists / Q000627:therapeutic use*; D000369:Aged, 80 and over; D000420:Albuterol / Q000627:therapeutic use; D012898:Autacoids; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004351:Drug Resistance; D004983:Ethanolamines / Q000627:therapeutic use*; D005260:Female; D005541:Forced Expiratory Volume; D000068759:Formoterol Fumarate; D006801:Humans; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy*; D011795:Surveys and Questionnaires
D000318:Adrenergic beta-Agonists; D012898:Autacoids; D001993:Bronchodilator Agents; D004983:Ethanolamines; D000420:Albuterol; D000068759:Formoterol Fumarate