NCIt definition : A cardioselective competitive beta-1 adrenergic receptor antagonist with antihypertensive
properties and devoid of intrinsic sympathomimetic activity. Metoprolol antagonizes
beta 1-adrenergic receptors in the myocardium, thereby reducing the rate and force
of myocardial contraction leading to a reduction in cardiac output. This agent may
also reduce the secretion of renin with subsequent reduction in levels of angiotensin
II thereby preventing vasoconstriction and aldosterone secretion.;