Penbutolol and propranolol: a comparison of their effects on antipyrine clearance in man.
The effects of two beta-adrenoceptor antagonists, penbutolol (administered on separate occasions as (+/-)- and (-)-forms) and propranolol, on the kinetics of antipyrine were studied in eight normal subjects. At the same degree of beta-adrenoceptor blockade, as assessed by the lowering of exercise tachycardia, propranolol decreased antipyrine clearance by 31 +/- 11 s.d.% (P less than 0.001) whereas neither of the two penbutolol formulations had a significant effect. The volume of distribution of antipyrine was unchanged following any of the beta-adrenoceptor antagonist treatments. The lack of effect of penbutolol on oxidative drug metabolism is not consistent with in vitro data suggesting a relationship between the lipid solubility of beta-adrenoceptor antagonists and inhibition of metabolism.
D000328:Adult; D000983:Antipyrine / Q000378:metabolism*; D006207:Half-Life; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007700:Kinetics; D008297:Male; D010394:Penbutolol / Q000494:pharmacology*; D005082:Physical Exertion; D011412:Propanolamines / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology*; D012463:Saliva / Q000032:analysis; D013237:Stereoisomerism
D011412:Propanolamines; D010394:Penbutolol; D011433:Propranolol; D000983:Antipyrine