Randomized, double-blind comparison of acute beta1-blockade with 50 mg metoprolol tartrate vs 25 mg carvedilol in normal subjects.
Differential efficacy of immediate-release metoprolol tartrate and carvedilol in the treatment of congestive heart failure remains a subject of ongoing debate. The degree of beta1-blockade can be assessed by percentage reduction of exercise heart rate. Twelve healthy subjects underwent symptom-limited cardiopulmonary exercise testing repeated weekly and 2 hours after randomized, double-blind administration of 50 mg metoprolol tartrate vs 25 mg carvedilol. Baseline heart rate, heart rate at 40% and 70% peak O2 consumption, and maximal exercise were significantly blunted more by metoprolol tartrate than by carvedilol (P<.05 for all). Peak O2 consumption was significantly reduced by metoprolol tartrate (P<.03) but not by carvedilol (P=.054). The change in O2 consumption was significantly correlated with the degree of beta1-blockade (r =0.45; P<.05). In healthy subjects, a higher degree of beta1-blockade is achieved with 50 mg metoprolol tartrate compared with 25 mg carvedilol.
Billeh
Rana
R
Division of Cardiology, New York University School of Medicine, New York, NY 10016, USA. ulrich.jorde@med.nyu.edu
Hirsh
David
D
Barker
Colin
C
Jorgensen
Birgit
B
Jeger
Raban
R
Ramanathan
Krishnan
K
Tseng
Chi-Hong
CH
Hudaihed
Alhakam
A
Haas
Francois
F
Jorde
Ulrich P
UP
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000328:Adult; D002227:Carbazoles / Q000494:pharmacology*; D000077261:Carvedilol; D004311:Double-Blind Method; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000494:pharmacology*; D008875:Middle Aged; D011412:Propanolamines / Q000494:pharmacology*
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D002227:Carbazoles; D011412:Propanolamines; D000077261:Carvedilol; D008790:Metoprolol