Adrenergic Antagonists

Adrenergic Antagonists:

Directly block adrenergic receptors
Have high degree of receptor specificity (unlike adrenergic agonists)  two types – alpha-adrenergic blocking agents and beta-adrenergic blocking agents

Effects of alpha-adrenergic blocking agents:
• lower blood pressure by blocking alpha1 receptors on arterioles and veins  vasodilation  reduction in blood pressure
• reduced contraction of smooth muscle in bladder  used for symptomatic relief in benign prostatic hyperplasia
• pheochromocytoma  increased secretion of catecholamines  hypertension from activation of alpha1 receptors  use alpha-adrenergic blocking agents
• suppression of symptoms in Raynaud’s disease – works by preventing the alpha mediated vasoconstriction

Adverse effects of alpha-adrenergic blocking agents:
hypotension (common side effect that limits therapeutic use)
• tachycardia

Effects of beta-adrenergic blocking agents:
• blockage of beta1 receptors in heart  decreased heart rate, decreased force of contraction, reduced velocity of impulse conduction through AV node.
• used for angina pectoris (decrease cardiac work  balance between oxygen demand and supply); hypertension; cardiac dysrhythmias (decrease rate of sinus node discharge and rate of conduction through AV node); heart failure.

Adverse effects of beta-adrenergic blocking agents:
• bradycardia
• reduction in cardiac output
• AV heart block
• 4-40% develop Raynaud’s Phenomenon
Find Weird and Wonderful Books at AbeBooks

We have not yet got to this page to finish it yet. We will eventually. Please contact us if you have something to contribute to it or sign up for our newsletter or like us on Facebook and Instagram or follow us on Twitter.

Page last updated: @ 3:15 am

Comments are closed.