Comparison of beta‐adrenoceptor blockers under maximal exercise (pindolol v metoprolol v atenolol).

Abstract

1 The time-related, comparative 3-adrenoceptor blocking effect of metoprolol 150 mg twice daily, atenolol 100mg once daily and pindolol 7.5 mg twice daily on heart rate, blood pressure, work performance, blood lactate, free fatty acids and plasma catecholamines was studied in ten males aged 19-25 years by means of repeated maximal bicycle exercise tests. 2 At steady state several differences in effects were noted among the drugs. These could be explained by differences in P3-selectivity, potency of the chosen drug-doses and intrinsic sympathomimetic activity (ISA). 3 This study emphasizes the importance of including strong sympathetic stimuli in any model used for comparing 3-adrenoceptor blockers with and without ISA in order not to underrate the effects of 1-adrenoceptor blockers with ISA.4 In the chosen doses pindolol was more effective, and atenolol less effective than metoprolol in suppressing heart rate and blood pressure responses to maximal exercise.

Effect of beta-adrenergic blockade on hormonal responses during continuous and intermittent exercise

“…However, the changes are modulated by the workload and the mode of exercise. The highly conflicting results from other studies with respect to the influence of beta blockade on catecholamines during exercise [7,[9][10][11]16] may therefore be explained by differences in technique and test models (type of exercise and degree of physical exercise) as well as differences in analytical methods of studying catecholamines.…”

“…As shown in this and previous studies [2,4,7,10,11,16], maximal exercise is a potent stimulus for the release of hormones of the adrenocortical axis and from the peripheral neuromotor system. Although maximal performance and the duration of exercise were comparable during intermittent, and continuous exercise, there were marked differences in hormonal responses between the two modes of exercise.…”

“…continuous exercise, intermittent exercise, epinephrine, norepinephrine, dopamine, prolactin, cortisol, renin, growth hormone Physical performance is determined by several factors, including cardiopulmonary function, energy-yielding processes, neuromuscular function, and central nervous mechanisms [1]. Exercise capacity depends on the relative importance of these factors and, to some extent, on the mode of exercise and its duration [1].During exercise, the neuroendocrine system is markedly activated [2][3][4][5], which is of importance for many of the cardiovascular and metabolic changes [6].It is well known that beta-blocker treatment may induce muscular fatigue and reduced work capacity [7][8][9][10][11], which is more pronounced with nonselective than with betas-selective beta blockers [7,9]. However, it is not clear whether this response is a consequence of their differential effects on circulating hormones.…”

“…It is well known that beta-blocker treatment may induce muscular fatigue and reduced work capacity [7][8][9][10][11], which is more pronounced with nonselective than with betas-selective beta blockers [7,9]. However, it is Lars Gullestad,* Lars Oystein Dolva,* Sverre Erik Kjeldsen,** Ivar Eide,** John Kjekshus* *Department of Internal Medicine, Baerum Hospital, Sandvika **Department of Internal Medicine, Ullev~ll Hospital, Oslo, Norway not clear whether this response is a consequence of their differential effects on circulating hormones.…”

Comparison of oxyfedrine and atenolol in angina pectoris‐a double‐ blind study.

“…It has been suggested that oxyfedrine has 240 a dual action on the heart and vascular system similar to the effects of nitroglycerine (Parratt & 220 MacKenzie, 1981). In experimental animals it -200 produces marked increase in coronary blood E flow due to arteriolar dilatation, a fall in the left n 180 atrial pressure and peripheral venodilation ' 160 (Parratt, 1974;Parratt & Mackenzie, 1981 is unlikely to explain all the actions of oxyfedrine, since pindolol, a drug with marked intrinsic sympathomimetic activity, does not result in maintenance of double product at angina threshold or peak exercise when compared with placebo (Erikssen et al, 1982).…”