Tolerance and beta-adrenergic blocking activity of flestolol, a short-acting beta blocker.
The tolerance and beta-adrenergic blocking activity of flestolol, a short-acting beta-blocker, was investigated in 30 subjects. Flestolol infused intravenously at doses up to 100 micrograms/kg/min was found to be well tolerated. A dose-dependent attenuation of isoproterenol-induced tachycardia and increase in systolic blood pressure occurred with flestolol at doses ranging from 0.5 to 15.0 micrograms/kg/min. The average percent reduction in isoproterenol-induced tachycardia (beta-blockade) at each dose of flestolol, 0.5, 2.5, 5.0, 15.0, and 50.0 micrograms/kg/min, was 15.1%, 45.9%, 67.0%, 85.9%, and 90.3%, respectively. The onset of beta-blockade occurred within 30 minutes. After the end of flestolol infusion there was a marked reduction in beta-blockade within 6 minutes, with complete recovery from beta-blockade within 30 to 45 minutes. There was a statistically significant (P less than 0.01) positive correlation between flestolol dosage and its blood levels (r = 0.91) as well as between the flestolol-induced beta-blockade and its dosage (r = 0.62).
P
P
Turlapaty
J
J
Burge
J
J
Hulse
R
R
Achari
V
V
Bell
H
H
Mosberg
A
A
Laddu
D000328:Adult; D000704:Analysis of Variance; D001794:Blood Pressure / Q000187:drug effects; D004341:Drug Evaluation; D005464:Fluorobenzenes; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007263:Infusions, Parenteral; D007545:Isoproterenol / Q000009:adverse effects; D008297:Male; D011412:Propanolamines / Q000009:adverse effects / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use; D013610:Tachycardia / Q000139:chemically induced / Q000188:drug therapy
D005464:Fluorobenzenes; D011412:Propanolamines; D007545:Isoproterenol; C047847:flestolol