Ppt chapter 31-1

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Adrenergic Blocking AntagonistsAdrenergic Blocking Antagonists

Chapter 31


Adrenergic Blocking AgentsAdrenergic Blocking Agents

• Definition

– Called sympatholytic drugs because they lyse, or block, the effects of the SNS

• Therapeutic and Adverse Effects

– Related to their ability to react with specific adrenergic receptor sites without activating them

• Action

– Prevent norepinephrine from activating the receptor


Site of Action of Adrenergic BlockersSite of Action of Adrenergic Blockers


Alpha- and Beta-Adrenergic Blocking Agents and Their Indications

Alpha- and Beta-Adrenergic Blocking Agents and Their Indications

• Carvedilol (Coreg): Hypertension, congestive heart failure (adult)

• Guanadrel (Hylorel): Hypertension in adults not responding to thiazide diuretics

• Guanethidine (Ismelin): Hypertension and renal hypertension

• Labetalol (Normodyne, Trandate): Hypertension, pheochromocytoma, clonidine withdrawal


Alpha- and Beta-Adrenergic Blocking Agents and Their Indications (cont.)Alpha- and Beta-Adrenergic Blocking Agents and Their Indications (cont.)

• Phentolamine (Regitine)

– Diagnosis of pheochromocytoma

– Management of severe hypertension during pheochromocytoma surgery

– Prevention of cell death with IV infiltration of norepinephrine or dopamine


Alpha- and Beta-Adrenergic Blocking Agents

Alpha- and Beta-Adrenergic Blocking Agents

• Actions

– Competitively block the effects of norepinephrine at the alpha and beta receptors throughout the SNS

– Prevents the signs and symptoms associated with sympathetic stress reaction and results in lower blood pressure, slower pulse, and increased renal perfusion with decreased renin levels

• Indications

– Essential hypertension


Alpha- and Beta-Adrenergic Blocking Agents (cont.)


• Pharmacokinetics

– Well absorbed and distributed throughout the body

– Metabolized in the liver and excreted in feces and urine

• Contraindications

– Bradycardia or heart block

– Shock or CHF




• Caution

– Bronchospasm

• Adverse Reactions

– Dizziness, insomnia, fatigue, nausea, vomiting, arrhythmias, hypotension, CHF, pulmonary edema, bronchospasm

• Drug-to-Drug Interaction

– Enflurane, halothane or isoflurance anesthetics

– Diabetic agents

– Calcium channel blockers


Prototype Alpha- and Beta-Adrenergic Blocking Agents

Prototype Alpha- and Beta-Adrenergic Blocking Agents


Nursing Considerations for Alpha- and Beta-Adrenergic Blocking Agents

Nursing Considerations for Alpha- and Beta-Adrenergic Blocking Agents

• Assessment: History and Physical Exam

• Nursing Diagnosis

• Implementation

• Evaluation


QuestionQuestion

What is an indication for use non-selective adrenergic blocking agents?

A. Essential hypertension

B. Malignant hypertension

C. Secondary hypertension

D. Malignant hyperthermia


AnswerAnswer

A. Essential hypertension

Rationale: The alpha- and beta-adrenergic blocking agents block all of the receptor sites within the SNS, which results in lower blood pressure, slower pulse, and increased renal perfusion with decreased renin levels. These drugs are indicated for the treatment of essential hypertension.


Alpha-Adrenergic Blocking AgentAlpha-Adrenergic Blocking Agent

• Actions

– Blocks postsynaptic alpha1 receptors, decreasing sympathetic tome in the vasculature and causing vasodilatation


– Absorbed after injection and is excreted in the urine


Alpha-Adrenergic Blocking Agent (cont.)Alpha-Adrenergic Blocking Agent (cont.)


– Allergy

– CAD or MI

• Caution

– Pregnancy and lactation


– Hypotension, orthostatic hypotension, angina, MI, CVA

– Arrhythmia, weakness, and dizziness


Alpha-Adrenergic Blocking Agent (cont.)Alpha-Adrenergic Blocking Agent (cont.)


– Ephedrine and epinephrine

– Alcohol


Prototype Alpha-Adrenergic Blocking Agent

Prototype Alpha-Adrenergic Blocking Agent


Nursing Considerations for Alpha-Adrenergic Blocking Agent

Nursing Considerations for Alpha-Adrenergic Blocking Agent



• Implementation

• Evaluation


Alpha1-Selective Adrenergic Blocking Agents

Alpha1-Selective Adrenergic Blocking Agents

• Doxazosin (Cardura): Used to treat hypertension; also effective in the treatment of benign prostatic hypertrophy

• Prazosin (Minipress): Used to treat hypertension, alone or in combination with other drugs

• Terazosin (Hytrin): Used to treat hypertension as well as BPH

• Tamsulosin (Flomax) and Alfuzosin (Uroxatral): Used only in the treatment of BPH


Alpha1-Selective Adrenergic Blocking Agents (cont.)


• Actions

– Block the postsynaptic alpha 1- receptor sites

– This causes a decrease in vascular tone and vasodilatation

• Indications

– BPH and hypertension


– Well absorbed, undergo extensive hepatic metabolism, excreted in the urine





– Allergy, lactation

• Caution

– CHF or renal failure


– Dizziness, weakness, fatigue

– Nausea, vomiting, abdominal pain, diarrhea

– Arrhythmias, hypotension, edema, CHF, and angina





– Vasodilators or antihypertensive drugs


Prototype Alpha1-Selective Adrenergic Blocking Agents

Prototype Alpha1-Selective Adrenergic Blocking Agents


Prototype Alpha1-Selective Adrenergic Blocking Agents (Continued)

Prototype Alpha1-Selective Adrenergic Blocking Agents (Continued)


Nursing Considerations for Alpha1-Selective Adrenergic Blocking Agents

Nursing Considerations for Alpha1-Selective Adrenergic Blocking Agents



• Implementation

• Evaluation


QuestionQuestion

Alpha1- selective adrenergic blocking agents are to be used with caution in what population of patients?

A. Those with hepatic disease

B. Those with hypotension

C. Those with congestive heart failure

D. Those with respiratory distress


AnswerAnswer

C. Those with congestive heart failure

Rationale: Alpha1-selective adrenergic blocking agents are used with caution in patients who have CHF or renal failure.


Beta-Adrenergic Blocking AgentsBeta-Adrenergic Blocking Agents• Actions

– Competitive blocking of the beta-receptors in the SNS

– Blocking of beta receptors in the heart and in the juxtaglomerular apparatus of the nephron

• Indications

– Treating cardiovascular problems

• Hypertension

• Angina

• Migraine headaches

– Preventing reinfarction after MI


Beta-Adrenergic Blocking Agents (cont.)Beta-Adrenergic Blocking Agents (cont.)


– Absorbed from GI tract and undergo hepatic metabolism


– Allergy

– Bradycardia, heart block, shock, or CHF

– COPD, asthma

• Caution

– Diabetes, hepatic dysfunction




– Fatigue, dizziness, depression, sleep disturbances

– Bradycardia, heart block, hypotension

– Bronchospasm

– Nausea, vomiting, diarrhea

– Decrease libido




– Clonidine

– NSAIDs

– Insulin or anti-diabetic medications


Prototype Beta-Adrenergic Blocking Agents

Prototype Beta-Adrenergic Blocking Agents


Prototype Beta-Adrenergic Blocking Agents (Continued)

Prototype Beta-Adrenergic Blocking Agents (Continued)


Nursing Considerations for Beta-Adrenergic Blocking Agents

Nursing Considerations for Beta-Adrenergic Blocking Agents



• Implementation

• Evaluation


Beta1-Selective Adrenergic Blocking Agents

Beta1-Selective Adrenergic Blocking Agents

• Advantage

– Do not usually block beta2-receptor sites, including the sympathetic bronchodilation

• Preferred for patients who smoke or have asthma, obstructive pulmonary disease, or seasonal or allergic rhinitis

• Uses

– Hypertension, angina, some cardiac arrhythmias


Beta1-Selective Adrenergic Blocking Agents (cont.)


• Actions

– Selectively block beta 1 receptors in the SNS


– Absorbed from GI tract

– Metabolized in liver and excreted in urine


– Allergy

– Sinus bradycardia, heart block, cardiogenic shock, CHF, and hypotension

• Caution

– COPD, diabetes, thyroid disease





– Fatigue, dizziness, sleep disturbances

– Bradycardia, heart block, CHF, hypotension

– Symptoms in respiratory tract range from rhinitis to bronchospasm

– Nausea, vomiting, diarrhea

– Decreased libido and impotence


– NSAIDs

– IV lidocaine


Prototype Beta1-Selective Adrenergic Blocking Agents

Prototype Beta1-Selective Adrenergic Blocking Agents


Prototype Beta1-Selective Adrenergic Blocking Agents (Continued)

Prototype Beta1-Selective Adrenergic Blocking Agents (Continued)


Nursing Considerations for Beta1-Selective Adrenergic Blocking Agents

Nursing Considerations for Beta1-Selective Adrenergic Blocking Agents



• Implementation

• Evaluation


Use of Adrenergic Blocking Agents Across the Lifespan

Use of Adrenergic Blocking Agents Across the Lifespan


QuestionQuestion

You are caring for a child who has been diagnosed with a heart problem. Propanolol has been ordered for this patient. What would be considered in calculating a child’s dose?

A. Child’s body weight and age

B. Child’s body mass

C. Child’s age in months and height

D. Child’s age and body mass index


AnswerAnswer

A. Child’s body weight and age

Rationale: Children are at greater risk for complications associated with the use of adrenergic blocking agents, including bradycardia, difficulty breathing, and changes in glucose metabolism. The safety and efficacy for use of these drugs has not been established for children younger than 18 years of age. If one of these drugs is used, the dosage for these agents needs to be calculated from the child’s body weight and age.

Ppt chapter 31-1

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