Adrenergic Receptor ANTAGONISTS Flashcards Preview

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Flashcards in Adrenergic Receptor ANTAGONISTS Deck (45):

Alpha Receptor Antagonists

1. Nonselective example?

2. Alpha 1 selective example?

1. phentolamine

2. prazosin


Beta Receptor Antagonists

1. Non-selective (first generation) example?

2. Beta 1 selective examples?

3. Non-selective (third generation) example? Why are they used?

1. propranolol

2. esmolol and metoprolol

3. Carvedilol and labetalol (used because they have additional vasodilator activities)


IGNORE Alpha adrenergic receptors mediate several functions:

1. Receptor and action on smooth muscle?

2. CNS receptor effect?

3. Presynaptic receptor effect?

4. Vagal effect? Why?

5. Two other basic effects?

1. Alpha 1 (some alpha 2) and contraction of arterial and venous smooth muscle

2. Suppress sympathetic output

3. Inhibit NE and ACh release

4. Increase vagal tone as reflex effect in response to increased BP

5. Facilitate platelet aggregation and regulate glucose/lipid metabolism (Alpha 2)


Alpha 1 receptor antagonists:

What does it do to catecholamines normal effect? Effect?


Inhibits catecholamine mediated vasoconstriction in arteries and veins --> reduces peripheral vascular resistance and BP. The decreased BP causes reflex increases in HR, CO, as well as fluid retention.

(inhibits vasoconstriction and increased BP in response to sympathomimetic amines)


Alpha 2 antagonists

What is an unwanted effect of alpha 2 antagonists?

Increases sympathetic outflow to the heart and blood vessels resulting in an increase in BP


What can alpha receptor antagonists do to the amount of glucose released?

Action on insulin release? Receptor?


Reduce glucose release

Facilitates insulin release; alpha 2



1. The drug associated?

2. Affects what receptors? How?

3. Primary results stem from blockade of receptors on ___ ___.

1. Phenoxybenzamine

2. Both alpha 1 and 2; irreversible

3. smooth muscle



1. Main action?

2. Impair pressor response to catecholamines resulting in?

1. DECREASE TPR, INCREASE CO (reflex), and possible tachycardia (from alpha 2 block)

2. hypotension, hypovolemia, and vasodilation



Therapeutic uses?

Pheochromocytoma (catecholamine secreting tumor that causes severe hypertension) in preparation to remove it (bc it will release catecholamines during surgery) to control episodes of severe hypertension and injury to the myocardium



Adverse effects? Why?

Due to low BP --> postural hypotension with reflex tachycardia and other arrhythmias

Due to impaired smooth muscle contraction of the vas deferens/ejaculatory ducts --> inhibition of ejaculation



1. Drug example?

2. Receptor antagonists? Mechanism?

3. CV effects?

1. Phentolamine

2. Both (nonselective); competitive inhibition

3. similar to phenoxybenzamine: Decreases TPR, Increases CO, possible tachycardia



Other than CV effects - what else can this cause?

Block 5HT receptors, release histamine (from mast cells), block K+ channels, stimulate GI smooth muscle, enhance gastric acid secretion (not good)



Therapeutic uses:

1. In regards to pheochromocytoma?

2. In regards to clonidine?

3. In regards to MAOIs?

4. What are 2 additional uses?

1. Decrease excessive hypertension and relieve pseudo-obstruction of the bowel 

2. Withdrawl of clonidine results in hypertensive crisis (this decreases hypertension)

3. With tyramine ingestion hypertensive crisis occurs (results in a decrease of hypertension)

4. (a) prevents dermal necrosis after the leakage of an alpha agonist (b) intracavernous injection for ED



Adverse Effects/Contraindications?

1. Hypotension

2. Reflex cardiac stimulation with tachycardia, cardiac arrhythmias, ischemia, and MI

3. GI stimulation resulting in abdominal pain/nausea (caused by increased motility by blocking SNS and increased vagal effects) and exacerbation of peptic ulcer


Alpha 1 receptor antagonists? (5)

Prazosin, Terazosin, Doxazosin, Alfuzocin, Tamsulosin



1. Receptor antagonist?

2. Pharmacological effects? Potent inhibitor of?

3. Why are these better: what do they not cause?

1. Alpha 1

2. Antihypertensive; cyclic nucleotide PDE (vasodilator)

3. Little postural hypotension, does NOT result in reflex tachycardia, no change in CO



Therapeutic effects?

Hypertension, CHF (doesnt prolong life!), BPH and associated lower urinary tract



Adverse effects and contraindications?

Primary first dose effect: marked postural hypotension and syncope within 30 to 90 minutes after an initial dose (because its very potent and causes increased vasodilation)



1. Potentcy compared to prazosin? Pharmacological effects?

2. Duration of action?

3. Therapeutic uses?

4. Adverse effects and contraindications?

1. Less potent; antihypertensive with no tachycardia or increase in CO, still a PDE inhibitor

2. 18 hours

3. Hypertension, better than prazosin for BPH (induces apoptosis in prostatic smooth muscle cells)

4. Primary first dose effect: marked postural hypotension and syncope within 30 to 90 minutes after an initial dose



1. Same as _____. Pharacological effects?

2. Duration of action?

3. Therapeutic use?

4. Adverse effects and contraindications?

1. Prazosin; Antihypertensive with no increase in CO or tachycardia, PDE inhibitor

2. 36 hours

3. Hypertension, better than prazosin for BPH (induces apoptosis in prostatic smooth muscle cells)

4. Primary first dose effect: marked postural hypotension and syncope within 30 to 90 minutes after an initial dose


Alfuzosin and Tamsulosin

1. Pharmacological effects?

2. Therapeutic uses? 

3. Specific effect with Tamsulosin?

4. Adverse effects  and contraindications?

1. Same as prazosin (except alpha 1a receptor antagonist): antihypertensive, no tachycardia or increase in CO, PDE inhibitor

2. BPH

3. Treats BPH with little effect on BP and thus less likely to cause orthostatic hypotension

4. Abnormal ejaculation


Beta adrenergic receptor antagonists have efficacy in the treatment of what 5 things?

Hypertension, ischemic heart disease, acute MI, CHF, and certain arrhythmias


What is an example of a pure competitive beta receptor antagonist (no ability to activate beta receptors)?



Beta 1 selective antagonists? (5)

Metoprolol, atenolol, acebutolol, bisoprolol, and esmolol


Partial agonists have what sort of activity? How do these work?

Examples? (6)

Intrinsic sympathomimetic activity (ISA); activate beta receptors partially in absence of catecholamines but less than a full agonist.

Pindolol, Acebutolol, Penbutolol, Carteolol, Labetolol, and Celiprolol


What drugs are used for beta-blockade independent, local anesthetic, or membrane stabilizing activity?

Propranolol, acebutolol, carvedilol (some pindolol, metoprolol, betaxolol, and labetolol)


Drugs with combined alpha 1 and beta blockade?

Labetalol, carvedilol, bucindolol


Beta blockers with additional vasodilating properties? (10)

carvedilol, labetalol, bucindolol, celiprolol, nebivolol, nipradilol, carteolol, betaxolol, bopindolol, and bevantolol


General beta antagonist cardiovascular effects? When are these effects greater?

Slow HR, decrease myocardial contractility, and these effects are greater when the SNS is activated vs the effects seen at rest


Beta receptor antagonist effects on CO:

1. Short term administration with propranolol results in what?

2. Long term administration with propranolol?

3. With beta1/alpha1 antagonists or beta antagonists with vasodilator properties - what occurs with CO and TPR?

1. DECREASED CO with compensatory TPR

2. TPR returns to its initial values (goes down)

3. CO is maintained with a greater fall in peripheral resistance


Beta receptor antagonist effect on Heart rate? (4)

Reduce sinus rate, decrease spontaneous rate of depolarization of ectopic pacemaker (proarrythmic - bad), slow conduction in the atria and in the AV node, increase the functional refractory period of the AV node


Beta antagonist CV effects during dynamic exercise:

1. HR/Contractility effects?

2. CO?

3. Work capacity?

4. Glucose metabolism and lipolysis?

5. Cardiac O2 supply to demand? Important in who?

1. Decreases exercise induced increase in HR and myocardial contractility

2. Less affected bc of an increase in SV

3. Decreased (not as bad with beta 1 selective agent)

4. Decreases activation 

5. Net improvement, important in CAD patients


Beta antagonist antihypertensive effect?

Lowers BP in patients with hypertension but not in patients with normal BP


Beta receptor antaconist effect on the pulmonary system:

1. Normal individual?

2. COPD individuals?

1. Little effect

2. Can cause life-threatening bronchoconstriction (less likely with beta1 selective or ISA antagonists)


Normal effect of catecholamines?

Nonselective beta blockers:

1. Effect on diabetes?

2. Metabolism of fat?

3. Effect on cholesterol? 


Promote glycogenolysis and mobilize glucose in response to hypoglycemia

1. Delay recovery from hypoglycemia

2. Block glycogenolysis and decrease release of FFA

3. Reduce HDL, increase LDL, and increase Triglycerides



Beta 1 Antagonist metabolic effects:

1. Exceptions to cholesterol?

2. Blunt what hypoglycemic symptoms?

3. Function in insulin sensitivity?

4. Exceptions?

1. Beta 1 antagonists can improve lipid profiles in dyslipidemic patients (celiprolol, carteolol, nebivolol, carvedilol, and bevantolol), also chronic use of celiprolol, carvedilol, and carteolol reduce triglycerides

2. tremor, tachycardia, and nervousness

3. Decrease

4. Vasodilating beta receptor antagonists may increase insulin sensitivity in patients with resistance: celiprolol, nipradilol, carteolol, and carvedilol


Clinical Therapeutic applications of beta receptor antagonists? (name drugs if available)

1. Hypertension

2. Angina - propranolol, metropolol, celiprolol

3. MI - propranolol (post MI) or metropolol (acute MI)

4 Ventricular arrhythmias

5. CHF

6. Pheochromocytoma - propranolol

7. Migraine

8. Emergency beta block - esmolol (perioperative)

9. Open angle glaucoma - esmolol


Third generation beta blockers have vasodilatory actions: 

1. __ adrenergic receptor blockade ( ____ )

2. Increased production of ___

3. __ agonist properties.

4. __ entry blockade( _____)

5. Opening of ___ channels

6. Antioxidant action ( _____)

1. alpha 1; carvedilol

2. NO

3. Beta 2

4. Ca++; carvedilol

5. K+

6. carvedilol


Carvedilol activities are great for what disease?



Beta antagonist adverse effects:

CV system:

1. Can induce ____ in susceptible patients

2. Exacerbate heart failure in what patients?

3. Can cause life threatening ____ in patients with heart blocks.


1. CHF

2. patients with compensated HF, acute MI, or cardiomegaly

3. bradycardia


Beta antagonist adverse effects:

CV system:

1. Not recommended with ____ ( calcium antagonists) or _____ agents that impair ___ node function or ___ conduction.

2. What else can occur? Why? (1 thing)

3. What occurs with abrupt discontinuation of the drug? why?

1. verapamil; antiarrhythmic; sinus; AV

2. Cold extremities - due to excessive vasoconstriction from beta block in limbs

3. Exacerbate angina and may increase the risk of sudden death because of receptor upregulation and hypersensitivity


Beta antagonist adverse effects:

Pulmonary function

1. What occurs in patients with bronchospastic diseases?

2. Which drugs are less likely to induce bronchospasm?

3. Contraindicated in patients with ____.

1. Life threatening increase in airway resistance

2. Beta 1 selective antagonists or ISA at beta 2

3. asthma


Beta antagonist adverse effects:

CNS effects?

Fatigue, sleep disturbances (including insomnia and nightmares) and depression


Beta antagonist adverse effects:


1. Delay recovery from?

2. Use caution in what patients? What agents are preferable?

1. Insulin-induced hypoglycemia

2. Diabetics; Beta 1 selective antagonists


Beta antagonist adverse effects:


1. How can poisoning manifest itself?

2. What should severe bradycardia be treated with?

3. Role of glucagon?

4. What could treat hypotension?

1. hypotension, bradycardia, prolonged AV conduction times, widened QRS complex, seizures, and depression may occur

2. Atropine

3. Acts as a positive chronotropic and inotropic factor on the heart and is independent of interactions with beta adrenergic receptors and thus can stimulate increased HR

4. large doses of isoproterenol or alpha receptor agonist