Unpredicted lack of effect of exercise on plasma concentrations of carvedilol.
In vitro studies have shown that beta-blockers are taken up into and released from adrenergic cells together with epinephrine and norepinephrine. Consequently, studies in humans revealed an increase in plasma concentrations of propranolol and atenolol during physical exercise. However, carvedilol has not been investigated in a similar fashion. Eleven hypertensive patients on long-term treatment (4 months) with carvedilol followed an exercise regimen. Plasma concentrations of carvedilol were determined at rest (9.7 +/- 3.4 ng/ml), during exercise (9.0 +/- 3.2 ng/ml), and after 15 min of recovery (9.1 +/- 2.7 ng/ml). Contrary to predictions, exercise had no effect on plasma concentrations of carvedilol, a finding that is in contrast to other beta-blockers. We conclude that carvedilol is not taken up into and released from adrenergic nerves during exercise, a feature that clearly distinguishes carvedilol from all other beta-adrenergic antagonists so far investigated.
Stoschitzky
Kurt
K
Division of Cardiology, Department of Medicine, Karl Franzens University, Graz, Austria. kurt.stoschitzky@kfunigraz.ac.at
Zweiker
Robert
R
Klein
Werner
W
Zitta
Sabine
S
Gruber
Leonhard
L
Lamprecht
Günter
G
Lindner
Wolfgang
W
D000319:Adrenergic beta-Antagonists / Q000097:blood* / Q000493:pharmacokinetics; D000959:Antihypertensive Agents / Q000097:blood* / Q000493:pharmacokinetics; D002227:Carbazoles / Q000097:blood* / Q000493:pharmacokinetics; D000077261:Carvedilol; D002851:Chromatography, High Pressure Liquid; D004562:Electrocardiography; D015444:Exercise; D006801:Humans; D006973:Hypertension / Q000378:metabolism / Q000503:physiopathology; D008875:Middle Aged; D011412:Propanolamines / Q000097:blood* / Q000493:pharmacokinetics
D000319:Adrenergic beta-Antagonists; D000959:Antihypertensive Agents; D002227:Carbazoles; D011412:Propanolamines; D000077261:Carvedilol