The pulmonary and extra-pulmonary effects of high-dose formoterol in COPD: a comparison with salbutamol.
OBJECTIVE
Formoterol, a beta(2) agonist with a rapid onset of effect and long duration of action, can be used as maintenance and reliever medication for asthma and COPD. We compared the pulmonary and extra-pulmonary effects of cumulative doses of formoterol and salbutamol in patients with COPD to assess efficacy and safety.


METHODS
In a randomized, double-blind, cross-over study, 12 patients with moderate to severe COPD inhaled, via Turbuhaler, 10 doses of formoterol (total metered dose, 120 microg, equivalent to a 90- microg delivered dose), salbutamol (total metered dose 2000 microg) or placebo at 2-min intervals on separate days. The effects on lung function (FEV(1) and PEF), heart rate, blood pressure, oxygen saturation, corrected QT interval (QTc), T-wave height and plasma potassium were assessed before each dose, 15 min after each dose, and at half-hourly intervals for 3 h following the final dose.


RESULTS
Inhalation of formoterol or salbutamol resulted in significant improvement in lung function (measured 30 min after the last dose) when compared with placebo. There were no clinically important or statistically significant changes in heart rate, QTc, T-wave height, plasma potassium, oxygen saturation, or systolic and diastolic blood pressures with formoterol or salbutamol. One patient developed ventricular trigeminy after both formoterol and salbutamol. She had had ventricular ectopics on her screening electrocardiogram.


CONCLUSIONS
Formoterol and salbutamol both produced significant improvement in lung function and were similarly well tolerated in high doses, as might be taken by a patient for relief of COPD symptoms.
Wellington Asthma Research Group, Department of Medicine, Wellington School of Medicine and Health Sciences, Wellington South, New Zealand.
Alexandra
A
Goldkorn
Patricia
P
Diotto
Carl
C
Burgess
Mark
M
Weatherall
Shaun
S
Holt
Richard
R
Beasley
Robert
R
Siebers
D000318:Adrenergic beta-Agonists / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D000368:Aged; D000420:Albuterol / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004983:Ethanolamines / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D005541:Forced Expiratory Volume; D000068759:Formoterol Fumarate; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D010366:Peak Expiratory Flow Rate; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000503:physiopathology
D000318:Adrenergic beta-Agonists; D004983:Ethanolamines; D000420:Albuterol; D000068759:Formoterol Fumarate