chapter 24

Chapter 24

Adrenergic Blocking Drugs

Learning Objectives

List the four types of adrenergic blocking drugs.

Explain the uses, general drug actions, general adverse reactions, contraindications, precautions, and interactions of the adrenergic blocking drugs.

Distinguish important preadministration and ongoing assessment activities the nurse should perform on the client taking an adrenergic blocking drug.

List nursing diagnoses particular to a client taking an adrenergic blocking drug.

Examine ways to promote an optimal response to therapy, how to manage common adverse reactions, nursing actions that may be taken to minimize orthostatic or postural hypotension, and important points to keep in mind when educating clients about the use of adrenergic blocking drugs.

Autonomic Nervous System

Division of the peripheral nervous system concerned with the functions essential to life of an organism and not consciously controlled (e.g., blood pressure, heart rate, and gastrointestinal activity)

Divided into two branches:

Sympathetic

Parasympathetic

Sympathetic Nervous System

Nerves are stimulated when the body is confronted with stressful situations such as danger, intense emotion, or severe illness

Fight, flight, or freeze response

Controls a person’s heart rate, breathing rate, and ability to divert blood to skeletal muscles

Adrenergic Blocking Drugs—Actions

Block neurotransmission in the sympathetic nervous system by directly by blocking the receptor or by indirectly preventing the release of norepinephrine.

Four Types of Adrenergic Blocking Drugs

Alpha (α)-adrenergic blocking

Beta (β)-adrenergic blocking

α/β-blocking

Centrally and peripherally acting antiadrenergic drugs

Alpha-Adrenergic Blocking Drugs—Actions

Interrupt or block alpha-adrenergic nerve stimulation resulting in vasodilation

Vasodilation occurs through relaxation of the smooth muscle of blood vessels

Alpha-Adrenergic Blocking Drugs—Uses

Hypertension caused by pheochromocytoma

Hypertension during preoperative preparation

Reduce ocular pressure during laser surgery

Prevent or treat tissue damage caused by extravasation of the drug dopamine

Alpha-Adrenergic Blocking Drugs—Adverse Reactions

Common Adverse Reactions:

Weakness

Orthostatic hypotension

Cardiac arrhythmias

Hypotension

Tachycardia

Other drug-specific adverse reactions

Alpha-Adrenergic Blocking Drugs—Contraindications and Precautions

Contraindicated in clients with:

known hypersensitivity to the drugs

coronary artery disease

Use cautiously in clients with:

pregnancy (pregnancy category C) or lactation

recent myocardial infarction

renal failure

Raynaud disease

Alpha-Adrenergic Blocking Drugs—Interactions

Beta-Adrenergic Blocking Drugs—Actions #1

Decreased stimulation of sympathetic nervous system on certain tissues

Block the nerve impulse from jumping the synapse area and continuing to the adjoining nerve ending

Decreased excitability of heart; decreased cardiac workload and oxygen consumption; provides membrane-stabilizing effects

Decreases the heart rate and dilates the blood vessels

When used for glaucoma, reduces production of aqueous humor in the anterior chamber of the eye

Examples: atenolol and metoprolol

Beta-Adrenergic Blocking Drugs—Actions #2

Beta-Adrenergic Blocking Drugs—Uses

Hypertension (first choice with stable angina)

Cardiac arrhythmia (ventricular or supraventricular tachycardia)

Migraine headaches

Heart failure

Angina pectoris

Glaucoma

Prevent reinfarction in clients with recent MI

Alert: discontinue these drugs slowly—taper; do not stop abruptly

Pharmacology in Practice Exercise #1

A nurse is caring for a client with glaucoma. The client is administered a beta-adrenergic blocking ophthalmic preparation, such as timolol. How will the effectiveness of the drug be determined?

Measure the intraocular pressure of the client

Monitor the blood pressure of the client

Monitor the respiratory rate of the client

Measure the pulse rate of the client

Beta-Adrenergic Blocking Drugs—Adverse Reactions #1

Generalized Adverse Reactions:

Orthostatic hypotension

Bradycardia

Dizziness, vertigo

Headache

Bronchospasm

Beta-Adrenergic Blocking Drugs—Adverse Reactions #2

Gastrointestinal System Reactions:

Hyperglycemia

Nausea

Vomiting

Diarrhea

Beta-Adrenergic Blocking Drugs—Contraindications and Precautions

Contraindicated in clients with:

known allergy to the beta-blockers

sinus bradycardia

second- or third-degree heart block

asthma or emphysema

hypotension

Use cautiously in clients with:

diabetes

thyrotoxicosis

peptic ulcer

Beta-Adrenergic Blocking Drugs—Interactions #1

Beta-Adrenergic Blocking Drugs—Interactions #2

Alpha/Beta-Adrenergic Blocking Drugs—Actions

Block the stimulation of both the alpha- and beta-adrenergic receptors, resulting in peripheral vasodilation

Examples: carvedilol and labetalol

Alpha/Beta-Adrenergic Blocking Drugs—Uses

Carvedilol—hypertension and heart failure to reduce progression of the disease

Labetalol—gestational hypertension alone or in combination with another drug

Alpha/Beta-Adrenergic Blocking Drugs—Adverse Reactions

Generalized Adverse Reactions:

Fatigue

Dizziness

Drowsiness, insomnia

Weakness

Diarrhea

Dyspnea

Chest pain, bradycardia, hypotension

Skin rash

Alpha/Beta-Adrenergic Blocking Drugs—Contraindications

Contraindicated in clients with:

known hypersensitivity to the drugs

bronchial asthma

decompensated heart failure

severe bradycardia

Alpha/Beta-Adrenergic Blocking Drugs—Precautions

Use cautiously in clients with:

Drug-controlled heart failure

chronic bronchitis

impaired hepatic or cardiac function

diabetes

pregnancy (pregnancy category C)

lactation

Alpha/Beta-Adrenergic Blocking Drugs—Interactions

Centrally and Peripherally Acting-Adrenergic Blocking Drugs—Actions

Peripherally acting: inhibit the release of norepinephrine from certain adrenergic nerve endings in the nervous system

Example: prazosin

Centrally acting: affects specific CNS centers, decreasing some of the activity in the sympathetic nervous system

Example: clonidine

Centrally and Peripherally Acting Antiadrenergic Drugs—Uses

Cardiac arrhythmias

Hypertension

Benign prostatic hypertrophy/hyperplasia (BPH)

Peripherally Acting Antiadrenergic Drugs—Adverse Reactions

Generalized Adverse Reactions:

Hypotension

Weakness

Lightheadedness

Bradycardia

Centrally Acting Antiadrenergic Drugs—Adverse Reactions

Generalized Adverse Reactions:

Dry mouth

Drowsiness

Sedation

Anorexia

Rash

Malaise

Weakness

Peripherally Acting Antiadrenergic Drugs—Contraindications and Precautions

Contraindicated in clients with:

known hypersensitivity to the drugs

active peptic ulcer or ulcerative colitis (reserpine)

Use cautiously in clients with:

renal impairment

cardiovascular disease

pregnancy and lactation

Centrally Acting Antiadrenergic Drugs—Contraindications and Precautions

Contraindicated in clients with:

known hypersensitivity to the drugs

active hepatic disease

antidepressant therapy using MAOIs

Use cautiously in clients with:

a history of liver disease or renal impairment

pregnancy and lactation

Centrally and Peripherally Acting Antiadrenergic Drugs—Interactions #1

Centrally and Peripherally Acting Antiadrenergic Drugs—Interactions #2

Pharmacology in Practice Exercise #2

A nurse is caring for a client taking both an antidepressant and an adrenergic blocking drug. Which of the following actions should the nurse perform when the client receiving adrenergic blocking drugs shows a dramatic decrease in blood pressure?

Monitor for excessive perspiration

Monitor for confusion

Adjust into a more comfortable position

Hold the drug dose

Nursing Process—Client Receiving an Adrenergic Blocking Drug #1

Preadministration Assessment

Will depend on the drug, the client, and the reason for administration.

Objective Data

General client appearance; dyspnea, peripheral edema, distended neck veins, cough

Vital signs (both arms and orthostatic BPs)

Electrocardiogram

Nursing Process—Client Receiving an Adrenergic Blocking Drug #2

Preadministration Assessment (continued)

Subjective Data

Current symptoms

Pain experience: onset, type, radiation, location, intensity, and duration

Precipitating factors of angina

Allergy history

History of other chronic health conditions

Nursing Process—Client Receiving an Adrenergic Blocking Drug #3

Ongoing Assessment

Observe the client for appearance of adverse reactions

Clients will monitor their own blood pressure while outpatient via home equipment, pharmacy, or fire station

Nursing Process—Client Receiving an Adrenergic Blocking Drug #4

Nursing Diagnoses

Impaired Comfort related to drying of secretions secondary to medication

Ineffective Tissue Perfusion: Peripheral related to hypotension

Injury Risk related to vertigo, dizziness, weakness, and syncope secondary to hypotension

Nursing Process—Client Receiving an Adrenergic Blocking Drug #5

Planning

Expected client outcomes depend on the reason for administration of the adrenergic blocking drug but may include:

Optimal response to therapy

Management of adverse drug reactions

Confidence in an understanding of the prescribed medication regimen

Nursing Process—Client Receiving an Adrenergic Blocking Drug #6

Implementation

Promoting Optimal Response to Therapy

Most drugs can be taken with or without food (except sotalol, which is given on an empty stomach)

Antiadrenergics should be given the same time every day

Monitor the client’s response to therapy; if symptoms worsen or are not controlled communicate with primary health care provider immediately

Nursing Process—Client Receiving an Adrenergic Blocking Drug #7

Implementation

Promoting Optimal Response to Therapy continued

If the drug is administered for hypertension and the client has a significant increase in blood pressure, administer the ordered dose and notify the primary health care provider—additional drug therapy

Beta-adrenergic blocking ophthalmic preparation: clients must continue follow-up examinations with ophthalmologist where intraocular pressure is measured

Nursing Process—Client Receiving an Adrenergic Blocking Drug #8

Implementation

Monitoring and Managing Client Needs

Impaired Comfort

Report adverse reactions to primary health care provider

Assist with measures to relieve dry mouth (frequent sips of water, sugarless hard candy or gum)

Nursing Process—Client Receiving an Adrenergic Blocking Drug #9

Implementation

Monitoring and Managing Client Needs

Impaired Comfort (continued)

Prevent constipation: encourage high-fiber foods and fluids (unless contraindicated)

Administer laxative or stool softener if ordered

Maintain record of bowel movements—inpatient

Lessen GI symptoms by administering drugs at a specific time in relation to meals, food, or with antacids

Nursing Process—Client Receiving an Adrenergic Blocking Drug #10

Implementation

Monitoring and Managing Client Needs

Ineffective Tissue Perfusion: Peripheral

During therapy take client’s blood pressure on the same arm before each dose is given and record on the MAR

Monitor blood pressure on both arms and take orthostatic blood pressure measurements

Nursing Process—Client Receiving an Adrenergic Blocking Drug #11

Implementation

Monitoring and Managing Client Needs

Ineffective Tissue Perfusion: Peripheral (continued)

Take an apical pulse and blood pressure before giving propranolol. Do not give if the pulse is below 60 beats/minute, if heart rate/rhythm is irregular, or if systolic blood pressure is less than 90 mm Hg

Clients with a life-threatening arrhythmia may receive an adrenergic blocking drug, such as propranolol, by the intravenous (IV) route; cardiac monitoring

Nursing Process—Client Receiving an Adrenergic Blocking Drug #12

Implementation

Monitoring and Managing Client Needs

Injury Risk

Clients receiving an adrenergic blocking drug may experience postural (orthostatic) hypotension

Hold the dose for a drop in 20 mm Hg systolic or a systolic below 90 mm Hg

Minimize first-dose effect if indicated by decreasing initial dose and administering at bedtime. Slowly increase dose over 2 weeks per provider orders.

Nursing Process—Client Receiving an Adrenergic Blocking Drug #13

Implementation

Monitoring and Managing Client Needs

Injury Risk (continued)

Call light should be placed nearby

Instruct clients to rise slowly and provide assistance with getting out of bed or a chair

Instruct client to sit or stand for 1 minute prior to rising or ambulating

Remain with client while ambulating

Teach client to avoid hot showers, baths, or standing in one place for prolonged periods

Pharmacology in Practice Exercise #3

A nurse is caring for a client on beta-adrenergic blocker therapy. The client is going to be administered lidocaine at the dental clinic. Which of the following interactions may occur and the nurse should instruct the client to ward the dental clinic staff if possible?

Increased risk of hypotension

Increased serum level of the beta blocker

Increased risk of paradoxical hypertensive effect

Increased side effect of the beta blocker

Nursing Process—Client Receiving an Adrenergic Blocking Drug #14

Implementation—Educating the Client and Family

Describe drug regimen and stress importance of continued and uninterrupted therapy when teaching client who is prescribed adrenergic blocking drug

Investigate barriers that might be leading to interruption of drug regimen (e.g., financial barriers) and make appropriate referrals if indicated

Educate the client regarding the cardiac conditions that can occur if the beta blocker is stopped suddenly

If ordered by the primary health care provider, stress importance of diet, weight loss in therapy of hypertension

Nursing Process—Client Receiving an Adrenergic Blocking Drug #15

Implementation—Educating the Client and Family

Teach client:

about DASH diet and refer to a registered dietician if indicated

to observe and report adverse reactions

to avoid driving or performing hazardous tasks

to check first with the primary health care provider before taking nonprescription drugs

to inform dentists and other providers about adrenergic blocking drug

to keep all primary health care provider appointments

to monitor blood pressure in the home setting

Nursing Process—Client Receiving an Adrenergic Blocking Drug $16

Evaluation

Was the therapeutic effect achieved? Was the client’s hypertension or other health condition controlled?

Were adverse reactions: identified, reported, and managed?

Dryness is managed and comfort maintained

Peripheral tissue perfusion is maintained

No evidence of injury

Did client and family express confidence and demonstrate understanding of drug regimen?

Turn and Talk—Case Study #1

A client presents to the emergency department via ambulance with nausea and substernal chest pain. After being assessed by the emergency department physician, it is determined that the client is having an acute myocardial infarction. The physician orders metoprolol (Lopressor) three bolus doses of 5 mg IV.

Before administering the three bolus doses of metoprolol (Lopressor) to the client, what should the nurse’s preadministration include?

What ongoing assessments should the nurse conduct with the client?

Turn and Talk—Case Study #2

The client is to be discharged with a prescription for metoprolol succinate ER (Toprol XL) 50 mg every morning. What should the nurse include in the client’s discharge instructions specifically in regard to the metoprolol?

Turn and Talk—Case Study #3

What should the nurse teach the client to improve the outcomes?