Beta-adrenergic blocking medication (beta-blockers) are commonly prescribed for patients with coronary artery disease and/or hypertension. Although there are many different classes of these drugs, all these medications compete with epinephrine and nor epinephrine for beta-adrenergic receptors in the heart. The end result is that beta-blockers reduce heart rate and the vigor or myocardial contraction, thus reducing the oxygen requirement of the heart