Randomized, double-blind comparison of acute beta1-blockade with 50 mg metoprolol tartrate vs 25 mg carvedilol in normal subjects.

Author(s): Billeh R, Hirsh D, Barker C, Jorgensen B, Jeger R, Ramanathan K, Tseng CH, Hudaihed A, Haas F, Jorde UP

Affiliation(s): Division of Cardiology, New York University School of Medicine, New York, NY 10016, USA. ulrich.jorde@med.nyu.edu

Publication date & source: 2006-09, Congest Heart Fail., 12(5):254-7.

Publication type: Randomized Controlled Trial; Research Support, Non-U.S. Gov't

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.