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Titolo:
Differing beta-blocking effects of carvedilol and metoprolol
Autore:
Stoschitzky, K; Koshucharova, G; Zweiker, R; Maier, R; Watzinger, N; Fruhwald, FM; Klein, W;
Indirizzi:
Graz Univ, Med Klin, Abt Kardiol, A-8036 Graz, Austria Graz Univ Graz Austria A-8036 ed Klin, Abt Kardiol, A-8036 Graz, Austria
Titolo Testata:
EUROPEAN JOURNAL OF HEART FAILURE
fascicolo: 3, volume: 3, anno: 2001,
pagine: 343 - 349
SICI:
1388-9842(200106)3:3<343:DBEOCA>2.0.ZU;2-Y
Fonte:
ISI
Lingua:
ENG
Soggetto:
CHRONIC HEART-FAILURE; IDIOPATHIC DILATED CARDIOMYOPATHY; PHARMACOLOGICAL PROPERTIES; TERM; BLOCKERS; BETA-1-ADRENOCEPTORS; DYSFUNCTION; BLOCKADE; EXERCISE;
Keywords:
carvedilol; metoprolol; beta-blockers; heart failure; melatonin;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Citazioni:
30
Recensione:
Indirizzi per estratti:
Indirizzo: Stoschitzky, K Graz Univ, Med Klin, Abt Kardiol, A-8036 Graz, Austria GrazUniv Graz Austria A-8036 rdiol, A-8036 Graz, Austria
Citazione:
K. Stoschitzky et al., "Differing beta-blocking effects of carvedilol and metoprolol", EUR J HE FA, 3(3), 2001, pp. 343-349

Abstract

Background: Metoprolol is a beta,-selective beta-adrenergic antagonist while carvedilol is a non-selective beta-blocker with additional blockades of alpha,-adrenoceptors. Administration of metoprolol has been shown to cause up-regulation of beta-adrenoceptor density and to decrease nocturnal melatonin release, whereas carvedilol lacks these typical effects of beta-blocking drugs. Aims: To compare beta-blocking effects of metoprolol and carvedilol when applied orally in healthy subjects. Methods: We investigated the effects of single oral doses of clinically recommended amounts of metoprolol (50, 100 and 200 mg) and carvedilol (25, 50 and 100 mg) to those of a placebo in a randomised, double-blind, cross-over study in 12 healthy male volunteers. Two hours after oral administration of the drugs heart rate and bloodpressure were measured at rest, after 20 min of exercise, and after 15 minof recovery. Results: Metoprolol tended to decrease heart rate during exercise (-21%, -25% and -24%) to a greater extent than carvedilol(-16%, -16% and -18%). At rest, increasing doses of metoprolol caused decreasing heart rates (62, 60 and 58 beats/min) whereas increasing doses of carvedilol caused increasing heart rates (62, 66 and 69 beats/min), 50 and 100 mg carvedilol failed to differ significantly from the placebo (71 beats/min). Conclusions: We conclude that. clinically recommended doses of carvedilol cause a clinically relevant beta-blockade in humans predominantly during exercise where it appears to be slightly (although not significantly) less effective than metoprolol. On the other hand, the effects of carvedilol on heart rate at rest appear rather weak, particularly in subjects with a low sympathetic tone. This might be caused by a reflex increase on sympathetic drive secondary to peripheral vasodilation resulting from the alpha-blocking effects ofthe drug. These results might be helpful in explaining why carvedilol, in contrast to metoprolol, may fail to cause up-regulation of beta-adrenoceptor density and does not decrease nocturnal melatonin release. This, in turn,may be a reason for the weak side-effects of carvedilol resulting from thebeta-blockade. In addition, our data might be of interest in the interpretation of the forthcoming results of the COMET trial, although it has to be emphasised that they were derived from healthy subjects and, therefore, cannot be directly extrapolated to patients with heart failure. (C) 2001 European Society of Cardiology. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 05/12/20 alle ore 01:18:07