Natural or synthetic Beta Adrenergic Blocking Agents typically bind to - but do not activate - beta-adrenergic receptors, blocking or diminishing physiologic beta-adrenergic agonist actions and activation of the sympathetic system. Reducing cardiac output, beta adrenergic antagonists are generally used for treatment of hypertension, cardiac arrythmias, angina pectoris, glaucoma, migraine headaches, and anxiety. (NCI04)