title: Randomized, double-blind comparison of acute beta1-blockade with 50 mg metoprolol tartrate vs 25 mg carvedilol in normal subjects.
abstract: 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.
authors.affiliation: Division of Cardiology, New York University School of Medicine, New York, NY 10016, USA. ulrich.jorde@med.nyu.edu
authors.forename: Rana
authors.initials: R
authors.lastname: Billeh
authors.forename: David
authors.initials: D
authors.lastname: Hirsh
authors.forename: Colin
authors.initials: C
authors.lastname: Barker
authors.forename: Birgit
authors.initials: B
authors.lastname: Jorgensen
authors.forename: Raban
authors.initials: R
authors.lastname: Jeger
authors.forename: Krishnan
authors.initials: K
authors.lastname: Ramanathan
authors.forename: Chi-Hong
authors.initials: CH
authors.lastname: Tseng
authors.forename: Alhakam
authors.initials: A
authors.lastname: Hudaihed
authors.forename: Francois
authors.initials: F
authors.lastname: Haas
authors.forename: Ulrich P
authors.initials: UP
authors.lastname: Jorde
mesh_terms: 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*
chemical_list: D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D002227:Carbazoles; D011412:Propanolamines; D000077261:Carvedilol; D008790:Metoprolol