Pilot study to compare the bronchodilator and metabolic responses to terbutaline infusion in seven asthmatic subjects--are they correlated?
We compared the changes in peak expiratory flow rate (PEFR), plasma potassium and plasma glucose during and after an infusion of the beta 2-agonist, terbutaline, in seven asthmatic subjects. Our aim was to establish whether these metabolic parameters could be correlated with PEFR. The percentage changes in PEFR were significantly correlated with the percentage changes in glucose (r = 0.60, P less than 0.001) and potassium (r = -0.64, P less than 0.001). Values for glucose and potassium changes were also correlated significantly with each other (r = 0.86, P less than 0.001). This suggests that in asthmatic subjects on beta 2-agonist treatment, plasma potassium could be used as a surrogate marker for beta 2 activity at bronchi. It also implies that the most effective beta 2-agonist bronchodilators will produce the greatest fall in plasma potassium. Further studies with a larger number of patients are needed to confirm this.
Haffner
C A
CA
Department of Medicine, Queen Elizabeth Hospital, Edgbaston, Birmingham, U.K.
Hughes
B
B
Kendall
M J
MJ
Holder
R
R
D000328:Adult; D001249:Asthma / Q000097:blood / Q000188:drug therapy*; D001786:Blood Glucose / Q000378:metabolism; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D010366:Peak Expiratory Flow Rate / Q000187:drug effects; D010865:Pilot Projects; D011188:Potassium / Q000097:blood; D013726:Terbutaline / Q000627:therapeutic use*
D001786:Blood Glucose; D013726:Terbutaline; D011188:Potassium