Choice of selective versus nonselective beta blockers: implications for exercise training.
Administration of beta blockers decreases tachycardia during exercise. In this regard, the effects of cardioselective drugs are similar to those of noncardioselective drugs. Beta blockers with partial agonist activity, however, may produce a lesser decrease in tachycardia during exercise. Cardioselective beta blockers have significantly less effect than noncardioselective drugs on isoproterenol-induced tachycardia. This may result from 2 factors: the failure of cardioselective drugs to block a beta 2 receptor-mediated vasodilator reflex tachycardia and their failure to block cardiac chronotropic beta 2 receptors. Exercise increases plasma catecholamine concentrations and the increases are larger in the presence of beta blockers. Cardioselective beta blockers produce larger increases. There is evidence for attenuation of exercise conditioning by beta blockers and this effect is probably shared by cardioselective and noncardioselective drugs. Beta blockers produce regulatory increases in beta receptor density, and physical training may do the opposite. The interaction between these 2 processes remains to be defined.
Kelly
J G
JG
D000319:Adrenergic beta-Antagonists / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D002395:Catecholamines / Q000097:blood; D005081:Exercise Therapy; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D005082:Physical Exertion; D011817:Rabbits; D011943:Receptors, Adrenergic, beta / Q000187:drug effects*; D013610:Tachycardia / Q000503:physiopathology
D000319:Adrenergic beta-Antagonists; D002395:Catecholamines; D011943:Receptors, Adrenergic, beta