Adrenergics II: Lecture 39 January 9, 2013

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Adrenergics II: Lecture 39 January 9, 2013 by Mind Map: Adrenergics II: Lecture 39 January 9, 2013

1. Drugs to Know

1.1. Beta Blockers

1.1.1. Propanolol

1.1.1.1. MOA: competitive antagonist at beta adrenergic receptors

1.1.1.1.1. Clinical Use: HTN, angina, cardiac arrhy. ischemic heart disease, many others (no effect on BP in normotensive ppl)

1.1.1.1.2. Special Info: 1st line for angina, it slows the AV node conduction in arrh. standard of care post-MI, NOT first line for HTN.

1.1.2. Metoprolol

1.1.2.1. MOA: competitive antagonist at beta1 adrenergic receptors (specifically beta1 blockade)

1.1.2.1.1. Clinical Use: HTN, angina, cardiac arrhy., ischemic heart disease, congestive heart failure (CHF)

1.1.2.1.2. Special Info: Metoprolol blocks beta 1 which is almost exclusively expressed in the heart; therefore, it has cardioselectivity!

1.1.3. Atenolol

1.1.3.1. MOA: competitive antagonist at beta1 adrenergic receptors (specifically beta1 blockade)

1.1.3.1.1. Clinical Use: HTN, angina, cardiac arrhy., ischemic heart disease, congestive heart failure (CHF)

1.1.3.1.2. Special Info: Like metoprolol, Atenolol blocks beta 1 which is almost exclusively expressed in the heart; therefore, it has cardioselectivity!

1.1.4. Esmolol

1.1.4.1. MOA: ultra-short acting beta blocker (10mins)

1.1.4.1.1. Clinical Use: IV given to limit catecholamine-mediated cardiac stimulation, especially in surgery (inhibits tachycardia)

1.1.4.1.2. Special Info: This drug has an very short half-life. It clears very fast!- This is because it gets hydrolized by enzymes in the blood.

1.1.5. Timolol

1.1.5.1. MOA: Non-selective beta blocker. Decreases aqueous humor production in eye thus reducing interocular pressure.

1.1.5.1.1. Clinical Use: Glaucoma (topical); hypertension and angina (systemic)

1.1.5.1.2. Special Info: enters CNS, longer half-life than propanolol and fewer side effects.

1.1.5.2. Issues:

1.1.5.2.1. Can have adverse effects on the heart and airways in patients with Asthma, pacemakers, and conduction pathway disease!

1.2. Intrinsic Sympathomimetic Activity

1.2.1. Pindolol

1.2.1.1. MOA: partial agonist at all beta adrenergic receptors

1.2.1.1.1. Clinical Use: Tx Hypertension

1.2.1.1.2. Special Info: This drug is good for ppl with bradycardia but high BP.

1.2.1.2. Advantages

1.2.1.2.1. Less cardiac depression (sub-max effect at beta 1 receptors

1.2.1.2.2. sill block exercise-induced increases in heart rate

1.2.1.2.3. Less tendency to cause bronchoconstriction (sub-max effect at beta 2)

1.2.1.2.4. Significantly reduces peripheral resistance (sub-max vasodilation at beta 2)

1.3. Mixed alpha/beta blockers

1.3.1. Labetalol

1.3.1.1. MOA: Racemic mixture with one isomer and alpha1 antagonist and another a nonselective beta antagonist (some partial b2 partial agonist activity)

1.3.1.1.1. Clinical Use: HTN, especially during hypertensive emergencies

1.3.1.1.2. Special Info: The drug is used during emergencies

1.3.2. Carvedilol

1.3.2.1. MOA: mixed alpha 1 nonselective beta antagonist

1.3.2.1.1. Clinical Use: HTN without reflex tachycardia (beta 1 blockade)

1.3.2.1.2. Special Info: Increases effects of calcium entry blockers, clonidine, digoxin, insulin, antidiabetics.

1.3.2.2. Contraindicated patients

1.3.2.2.1. Asthma patients

1.3.2.2.2. Bradycardia patients

1.4. Prazosin

2. Concepts/Mechanisms to Know

2.1. Sympathomimetic effects on BP/HR

2.2. Baroreceptor Reflex

2.3. Epinephrine Reversal

2.4. Beta Blocker withdrawal syndrome

2.4.1. beta blocker withdrawal syndrome.png

2.5. Rebound

2.6. Intrinsic sympathomimetic Activity

2.7. Cardioselectivity

2.8. Adrenergic RECEPTORS

2.9. Side Effects of Receptor Block/Action