Adrenergic-Blocking Drugs

Question 1

Adrenergic Blockers

Answer 1

Bind to adrenergic receptors but inhibit or block stimulation of the sympathetic nervous system (SNS)

Have the opposite effect of adrenergic drugs

Inhibit (lyse) sympathetic stimulation

Question 2

A1 receptors effects: 2

Answer 2

constrict BVs and visceral organ sphincters

dilate pupils

Question 3

A2 receptors effects: 2

Answer 3

inhibit NE release from adrenergic terminals

inhibit insulin secretion

Question 4

B1 receptors effects: 3

Answer 4

increase HR

inctease FOC

stimulate kidneys to release renin

Question 5

B2 receptors effects: 3

Answer 5

relaxes uterus

dilate BVs and bronchioles

relaxes smooth muscle walls of GI and urinary visceral organs

Question 6

Adrenergic blockers also known as:

Answer 6

Adrenergic antagonists
Sympatholytics
α-blockers, β-blockers, and α-β–blockers

Classified by the type of adrenergic receptor they block
α1- and α2-receptors
β1- and β2-receptors

Question 7

Drug Effects and Indications: α-Blockers

Answer 7

Cause both arterial and venous dilation, reducing peripheral vascular resistance and blood pressure (BP)

Used to treat hypertension

Effect on receptors on prostate gland and bladder decreases resistance to urinary outflow, thus reducing urinary obstruction and relieving the effects of benign prostatic hyperplasia (BPH).

Question 8

Drug Effects and Indications: α-Blockers

Answer 8

Used to control and prevent hypertension in patients with pheochromocytoma

Raynaud’s disease, acrocyanosis, and frostbite

Question 9

*Phentolamine

Answer 9

Quickly reverses the potent vasoconstrictive effects of extravasated vasopressors such as norepinephrine or epinephrine

Restores blood flow and prevents tissue necrosis

Question 10

α-Blockers: Adverse Effects

Answer 10

Body system/adverse effects

Cardiovascular: Palpitations, orthostatichypotension, tachycardia, edema, chest pain

Central nervous system: Dizziness, headache, anxiety, depression, weakness, numbness, fatigue

Gastrointestinal: Nausea, vomiting, diarrhea, constipation, abdominal pain

Other: Incontinence, dry mouth, pharyngitis

Question 11

Common α-Blockers

Answer 11

phentolamine mesylate (Rogitine®)
tamsulosin (Flomax®)

Question 12

**phentolamine (Rogitine®)

what receptor does it block?

what does it reduce?

establish a diagnosis of?

Most commonly used to treat the extravasation of?

Answer 12

α-Blocker that reduces systemic vascular resistance and is sometimes used to treat hypertension

Establish a diagnosis of pheochromocytoma

Most commonly used to treat the extravasation of vasoconstricting drugs such as norepinephrine, epinephrine, and dopamine

Contraindicated in known hypersensitivity, myocardial infarction (MI), and coronary artery disease

Question 13

tamsulosin (Flomax®)

Answer 13

α-Blocker used primarily to treat BPH; exclusively indicated for male patients

Contraindications: known drug allergy and concurrent use of erectile dysfunction drugs such as sildenafil

Adverse effects: headache, abnormal ejaculation, rhinitis, and others

Question 14

β-Blockers

Answer 14

Block stimulation of β-receptors in the SNS

Compete with norepinephrine and epinephrine

Can be selective or nonselective
-Cardioselective β-blockers or β1-blocking drugs
-Nonselective β-blockers block both β1-receptors and β2-receptors.

β2-Receptors are located primarily on the smooth muscles of the bronchioles and blood vessels.

Question 15

*carvedilol, labetalol

which receptor does it block?

Answer 15

α-Receptor–blocking activity, especially at higher dosages

Question 16

acebutolol, pindolol

Answer 16

Not only block β-adrenergic receptors but also partially stimulate them

Question 17

β1-Receptors

Located primarily on the?

β-Blockers selective for these receptors are called ______ β-blockers.

Answer 17

Located primarily on the heart

β-Blockers selective for these receptors are called cardioselective β-blockers.

B1: increase HR, FOC, and renin release

Question 18

β2-Receptors

Located primarily on?

Answer 18

Located primarily on smooth muscle of bronchioles and blood vessels

B2: dilates BVs and bronchioles, relaxes smooth muscle walls of GI and GU visceral organs, relaxes uterus

Question 19

Cardioselective β-blockers (β1)

drug effects; HR, SA node, AV node

decrease_____ thus reducing______

Answer 19

Reduce SNS stimulation of the heart

Decrease heart rate

Prolong sinoatrial node recovery

Slow conduction rate through the atrioventricular (AV) node

Decrease myocardial contractility, thus reducing myocardial oxygen demand

Question 20

Nonselective β-blockers (β1 and β2)

drug effects on heart and respiratory system

Answer 20

Cause same effects on heart as do cardioselective ß-blockers

Constrict bronchioles, resulting in narrowing of airways and shortness of breath

Produce vasoconstriction of blood vessels

Question 21

β-Receptors: Indications

Answer 21

Angina, MI, hypertension
-Decrease demand for myocardial oxygen

Cardioprotective
-Inhibit stimulation from circulating catecholamines

Dysrhythmias

Glaucoma (topical use)

Migraine headache
-Lipophilicity allows entry into central nervous system.

Question 22

β-Blockers: Adverse Effects

Answer 22

Nonselective β-blockers may interfere with normal responses to hypoglycemia (tremor, tachycardia, nervousness).

May mask signs and symptoms of hypoglycemia

Use with caution in patients with diabetes mellitus.

Question 23

*Atenolol (Tenormin®)

Commonly used to

Management of ______ to help block the symptoms of excessive thyroid activity

Answer 23

Cardioselective β-blocker

Commonly used to prevent future heart attacks in patients who have had one attack

Hypertension and angina

Management of thyrotoxicosis to help block the symptoms of excessive thyroid activity

Available for oral use

Question 24

*Carvedilol

class?

action

Answer 24

Nonselective β-blocker, an α1-blocker, a calcium channel blocker, and possibly an antioxidant

Uses: heart failure, hypertension, and angina

Slows progression of heart failure and decreases the frequency of hospitalization in patients with mild to moderate (class II or III) heart failure

Most commonly added to digoxin, furosemide, and angiotensin-converting enzyme inhibitors when used to treat heart failure

Question 25

*esmolol (Brevibloc®)

primary use

Answer 25

Very strong short-acting β1-blocker.

Primary use: acute situations, to provide rapid temporary control of the ventricular rate in patients with supraventricular tachydysrhythmias

Administered intravenously

Question 26

Nonselective β-Blockers drugs

Answer 26

labetalol (Trandate®)
propranolol (Inderal®)

Question 27

Cardioselective β-Blockers

Answer 27

metoprolol (Lopressor®)

Question 28

Adrenergic-Blocking Drugs: Nursing Implications

Answer 28

Assess for allergies and perform a thorough cardiac assessment.
-Any pre-existing condition that might be exacerbated by the use of these drugs might be a contraindication to their use.
Encourage patients to take medications as prescribed.
Instruct patients that these medications should never be stopped abruptly.
Inform patients to report constipation or the development of urinary hesitancy or bladder distention.
Teach patients to change positions slowly to prevent or minimize postural hypotension.
Instruct patients to avoid caffeine (causes excessive irritability).
Instruct patients to avoid alcohol ingestion and hazardous activities until blood levels become stable.
Instruct patients to notify their physicians if palpitations, dyspnea, nausea, or vomiting occurs

Question 29

Remember that α-blockers may precipitate

Answer 29

hypotension

Question 30

Remember that some β-blockers may precipitate

Answer 30

bradycardia, hypotension, heart block, heart failure, and bronchoconstriction.

Question 31

Always take ______ measurement before administration of these medications

Answer 31

blood pressure measurement

Question 32

You may need to hold administration of a β-blocker (and other antihypertensives) if the BP is ___________________________or pulse is less than_______ (please check facility protocols for best practice)

Answer 32

You may need to hold administration of a β-blocker (and other antihypertensives) if the BP is 90/60 or 30 mmhg lower than normal or pulse is less than 60 bpm (please check facility protocols for best practice)

Question 33

Adrenergic blockers

Possible drug interactions may occur with:

Answer 33

Antacids (aluminum hydroxide type)
Antimuscarinics or anticholinergics
Diuretics and cardiovascular drugs
Neuromuscular blocking drugs
Oral hypoglycemic drugs

Question 34

Monitor for therapeutic effects.

Answer 34

Decreased chest pain in patients with angina
Return to normal BP and heart rate
Other specific effects, depending on the use

Question 35

β-Blocking Drugs: Nursing Implications

Answer 35

Rebound hypertension or chest pain may occur if these medications are discontinued abruptly.

Instruct patients to notify their physicians if they become ill and are unable to take medication.

Inform patients that they may notice a decrease in tolerance for exercise (dizziness and fainting may occur with increased activity), and have patients notify their physicians if these problems occur.

Question 36

Inform patients to report the following to their physicians:

Answer 36

Weight gain of more than 1 kg in 24 hours or 2.3 kg in 1 week
Edema of the feet or ankles
Shortness of breath
Excessive fatigue or weakness
Syncope or dizziness