Mod 5 Adrenergic blockers

Question 1

Adrenergic Blockers

Answer 1

 Bind to adrenergic receptors, but inhibit or block stimulation of the sympathetic nervous system (SNS)
 (alpha) (alpha)–blockers and (beta)beta–blocker

Question 2

Adrenergic Blockers (cont’d)

Answer 2

 Have the opposite effect of adrenergic drugs
 Inhibit—or lyse—sympathetic stimulation
 Also known as:
 Adrenergic antagonists
 Sympatholytics
 Alpha-blockers, beta-blockers, or alpha-beta blockers

Question 3

Adrenergic Blockers (cont’d)

Answer 3

Classified by the type of adrenergic receptor they block
1 and 2
receptors

Question 4

Drug Effects and Indications:

Alpha-Blockers

Answer 4

Cause both arterial and venous dilation,
reducing peripheral vascular resistance and
BP
 Used to treat hypertension
 Effect on receptors on prostate gland and
bladder decreases resistance to urinary
outflow, thus reducing urinary obstruction and relieving effects of BPH

Question 5

Drug Effects and Indications:

Alpha-Blockers (cont’d)

Answer 5

 Used to control and prevent hypertension in patients with pheochromocytoma
 Phentolamine
 Quickly reverses the potent vasoconstrictive effects of extravasated vasopressors such as
norepinephrine or epinephrine
 Restores blood flow and prevents tissue necrosis

Question 6

–Blockers: Adverse Effects Blockers: Adverse Effects

Answer 6

Body System Adverse Effects
Cardiovascular Palpitations, orthostatic Palpitations, orthostatic
hypotension, tachycardia, edema, dysrhythmias, chest pain
CNS Dizziness, headache, drowsiness,
anxiety, depression, vertigo,
weakness, numbness, fatigue

Question 7

–Blockers: Adverse Effects (cont’d) Blockers: Adverse Effects (cont’d)

Answer 7

Body System Adverse Effects
Gastrointestinal Nausea, vomiting, diarrhea, 
constipation, abdominal pain
Other Incontinence, nosebleed
tinnitus, dry mouth,  pharyngitis,,
rhinitis

Question 8

Common –Blockers Blockers

Answer 8

 phenoxybenzamine HCl (Dibenzyline)
 phentolamine (Regitine)
 prazosin (Minipress)
 tolazoline (Priscoline)

Question 9

–Blockers

Answer 9

 Block stimulation of  receptors in
the SNS
 Compete with Compete with norepinephrine and epinephrine
 Selective and nonselective –blockers
 Nonselective –blockers block both
1 and 2 receptors

Question 10

 Receptors

Answer 10

 Beta1 receptors
 Located primarily on the heart
 Beta-blockers selective for these receptors 
are called cardioselective beta-blockers
 Beta2 receptors
 Located primarily on smooth muscle of 
bronchioles, blood vessels and uterus

Question 11

Mechanism of Action

Answer 11

 Cardioselective beta-blockers (beta1)
 Reduce SNS stimulation of the heart
 Decrease heart rate
 Prolong SA node recovery
 Slow conduction rate through the AV node
 Decrease myocardial contractility, thus reducing myocardial oxygen demand

Question 12

Mechanism of Action

Answer 12

 Nonselective beta-blockers (beta1
and beta2)
 Cause same effects on heart as cardioselective beta-blockers
 Constrict bronchioles, resulting in narrowing of airways and shortness of breath
 Produce vasoconstriction of blood vessels

Question 13

Indications

Answer 13

 Angina
 Decreases demand for myocardial oxygen
 Cardioprotective
 Inhibits stimulation from circulating 
catecholamines
 Dysrhythmias
 Class II antidysrhythmic 
 Migraine headache
 Lipophilicity allows entry into CNS

Question 14

Indications

Answer 14

Antihypertensive
Heart failure
Glaucoma (topical use)

Question 15

Adverse Effects: –Blockers

Answer 15

Body System Adverse Effects
Blood Agranulocytosis,  thrombocytopenia
Cardiovascular AV block, bradycardia, 
heart failure peripheral vascular
insufficiency
CNS Dizziness, mental depression, 
lethargy, hallucinations

Question 16

Adverse Effects:

Adrenergic–Blocking Drugs

Answer 16

–blockers blockers
Body System Adverse Effects
Gastrointestinal Nauseaausea,, dry mouth vomiting,,
diarrhea, cramps, ischemic colitis
Other
Impotence, rash, alopecia, Impotence, rash,
bronchospasm

Question 17

–Blockers: Examples

Answer 17

 acebutolol  (Sectral Sectral)
 carvedilol (Coreg)
 atenolol (Tenormin Tenormin)
 esmolol (Brevibloc)
 carvedilol (Coreg)
 labetalol (Trandate Trandate)
 metoprolol (Lopressor)
 esmolol (Brevibloc)
 sotalol (Betapace Betapace)
propranolol (Inderal Inderal)