at a dose of 2.9 to 5.4 mg/kg , steady-state plasma concentrations of metoprolol varied 17-fold ( from 20 to 341 ng/ml ) between patients and correlated with the interindividual variability in isoproterenol antagonism ( r = 0.58 , p less than 0.05 ) and decrease in exercise tachycardia ( r = 0.65 , p less than 0.01 ) .
C0022245
isoproterenol
C0039231
tachycardia