Effects of regular salmeterol on lung function and exercise capacity in patients with chronic obstructive airways disease.
BACKGROUND
The aim of this study was to evaluate the effects of single and chronic dosing with salmeterol on exercise capacity and lung function in patients with chronic obstructive pulmonary disease.


METHODS
Twenty nine patients of mean (SE) age 64 (1.5) years, forced expiratory volume in one second (FEV1) 42(3)% of predicted, and 5-15% reversibility to salbutamol 200 micrograms were randomised to receive four weeks treatment with salmeterol 50 micrograms twice daily or placebo in a double blind crossover fashion with a one week washout period in between. Measurements of spirometric parameters, static lung volumes, and exercise capacity were made one and six hours after a single dose, and six hours after the final dose of salmeterol or placebo.


RESULTS
Salmeterol produced a small increase in FEV1 at one and six hours after a single dose, and this was maintained after chronic dosing (mean difference and 95% CI versus placebo): single dosing at one hour 0.07 (95% CI 0.02 to 0.11) 1, single dosing at six hours 0.16 (95% CI 0.09 to 0.22) 1, chronic dosing at six hours 0.11 (95% CI 0.03 to 0.19) 1. The increase in forced vital capacity (FVC) was greater with salmeterol than with placebo six hours after single but not chronic dosing: single dosing at six hours 0.17 (95% CI 0.04 to 0.29) 1, chronic dosing at six hours 0.02 (95% CI -0.18 to 0.22) 1. Slow vital capacity was increased after treatment with salmeterol compared with placebo one and six hours after single but not after chronic dosing. There were no significant differences in static lung volumes or exercise capacity after single or chronic dosing with salmeterol compared with placebo. Patients reported a significantly lower Borg score for perceived exertion following the six minute walk after chronic treatment with salmeterol compared with placebo.


CONCLUSIONS
Salmeterol produced a small improvement in spirometric values compared with placebo consistent with the degree of reversibility originally shown by the subjects to salbutamol 200 micrograms. This was not associated with improvements in static lung volumes or exercise capacity, but there was some symptomatic benefit in that patients were able to walk the same distance in six minutes with less perceived exertion.
Grove
A
A
Department of Clinical Pharmacology, Ninewells Hospital and Medical School, Dundee, UK.
Lipworth
B J
BJ
Reid
P
P
Smith
R P
RP
Ramage
L
L
Ingram
C G
CG
Jenkins
R J
RJ
Winter
J H
JH
Dhillon
D P
DP
D000420:Albuterol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D001993:Bronchodilator Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D018592:Cross-Over Studies; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006339:Heart Rate; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000502:physiology; D012119:Respiration / Q000187:drug effects*; D000068299:Salmeterol Xinafoate; D014797:Vital Capacity / Q000187:drug effects
D001993:Bronchodilator Agents; D000068299:Salmeterol Xinafoate; D000420:Albuterol; D010100:Oxygen