week 4- Adrenergic-Blocking Agents

Question 1

Adrenergic Blockers

Answer 1

Bind to adrenergic receptors, to inhibit or block stimulation of the sympathetic nervous system (SNS) (fight &flight response)

Alpha-blockers and beta-blockers

Question 2

ADRENERGIC BLOCKERS Have the opposite effect of adrenergic agents

Answer 2

.

Question 3

Also known as:

Answer 3

Adrenergic antagonists
OR
Sympatholytics
These drugs are antagonists –bind to adrenergic receptors to inhibit or block stimulation by epinephrine or norepinephrine (sympatholytics)

Question 4

classified

Answer 4

Classified by the type of adrenergic receptor they block

Alpha 1
–Located on the cells, muscles, organs that the nerve is stimulating—post synaptic effector cells

Alpha 2
—Located on nerves that initiating the stimulation –pre synaptic effector nerve endings

Beta 1
—Primarily located on the heart
Decrease heart rate and blood pressure

Beta 2
—Located on smooth muscles of the blood vessels & bronchioles
Block the effects of the adrenergic receptors

Question 5

The effects of the adrenergic blockers

Answer 5

differ depending on the cells or tissue that they exert their action on.

Question 6

Adrenergic Blockers Used For:

Answer 6

 Hypertension: causes vasodilatation of the blood vessels
 Tachycardia: blocks stimulating effects
 Cardiac arrhythmias: prevention of tachycardia, controlled stimulation
 Angina: vasodilatation, decreased O2 consumption
 Migraine headaches: vasoconstriction of cerebral vessels (ergotamine)
 Uterine bleeding: causes vasoconstriction (ergotamine)
 Labour uterine contraction: vasoconstriction (oxytocin)
 Benign prostatic hyperplasia BPH: relaxation and dilatation of the vascular area and smooth muscle of the prostate
 Glaucoma: vasodilatation

Question 7

Prazosin (Minipress)

Answer 7

Cause both arterial and venous dilation, reducing peripheral vascular resistance and BP
Used to treat hypertension

Question 8

Tamsulosin (Flomax) (specific for BPH)

Answer 8

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

Question 9

Ergot alkaloids

Answer 9

migraines

Question 10

Phentolamine (Alpha Blocker)

Answer 10

Quickly reverses the potent vasoconstrictive effects of vasopressors such as norepinephrine or epinephrine
Restores blood flow and prevents ischemic tissue leading to tissue necrosis
Causes vasodilation

Question 11

Alpha-Blockers: Side Effects

Answer 11

Palpitations, orthostatic hypotension, tachycardia, edema, dysrhythmias, chest pain
Dizziness, headache, drowsiness, anxiety, vertigo, weakness, numbness, fatigue
Incontinence, nosebleed, tinnitus, dry mouth, pharyngitis, rhinitis

Question 12

Common Agents

Answer 12

 phentolamine (Regitine)
reversal of vasoconstriction from epinephrine and norepinephrine

 prazosin (Minipress)
for treatment of hypertension

 tamsulosin (Flomax)
BPH (benign prostate hyperplasia)

 ergotamine tartrate (Ergostat)
for uterine bleeding or heavy menstrual bleeding

Question 13

Beta-Blockers

Answer 13

Block stimulation of beta-receptors in the SNS

Competes with norepinephrine and epinephrine

Beta Blockers can be either depending on the receptors they block:
Nonselective and selective beta-blockers
also called
Nonspecific or cardioselective beta-blockers

Question 14

Beta1-receptors

Answer 14

 Located primarily on the heart
 Beta-blockers selective for these receptors are called cardioselective beta-blockers
 Effective for cardiac arrhythmias and hypertension
 Effects heart contractility, heart rate and conduction resulting in bradycardia, decrease contractility and decrease conduction
 ie. atenolol, propranolol, metoprolol

Question 15

Beta2-receptors

Answer 15

Located primarily on smooth muscles of bronchioles and blood vessels

Blocking bronchodilating effect from the smooth muscle causes relaxation - resulting in bronchoconstrition of the lungs

Use with caution in patients with lung disorders, asthmatics. Can worsen the effects and put the patient at risk for respiratory distress

Question 16

Mechanism of Action -Cardioselective (beta1)

Answer 16

Reduce SNS stimulation of the heart
Decreases heart rate
Prolongs SA node recovery
Slows conduction rate through the AV node
Decreases myocardial contractility, thus decreasing myocardial oxygen demand
Peripheral pooling of blood due to relaxation of smooth muscles (Beta 2) leads to orthostatic hypotension

Question 17

Mechanism of Action- Nonspecific (beta1 and beta2)

Answer 17

Effects on heart: Same as cardioselective

Bronchioles: Constriction, resulting in narrowing of airways and shortness of breath

Peripheral Vessels: Vasodilation

Question 18

Side Effects: Beta-Blockers

Answer 18

AV block, bradycardia, heart failure, peripheral vascular vasodilation
Dizziness, lethargy
Nausea, vomiting, diarrhea, cramps
Impotence, rash, alopecia, bronchospasm

Question 19

beta blockers types

Answer 19

Atenolol
-cardioselective, used to prevent future MI post MI, hypertension angina
Acebutolol
Used for hypertension, ventricular and supraventricular dysrhythmias and angina
Used immediate period post MI
Esmolol
Very potent, short acting, only IV, used in emergency situation for rapid temporary control of arrhythmias
Labetolol
Blocks both alpha and beta adrenergic receptors
Used for severe hypertension and hypertension emergencies to quickly lower BP
Metoprolol
Used in post MI pts
Propranolol
Non selective, first beta blocker agent
Used in the treatment of digoxin toxicity, tachyarrhythmias, hypertrophic sub-aortic stenosis, thyrotoxicosis, migraine headaches, adrenal tumors
Sotolol
Non-selective, very potent antidysrhythmic, treat arrhythmias—often for the more difficult arrhythmias, used as a cardioversion drug

Question 20

alpha-blockers may precipitate hypotension

Question 21

Remember that some beta-blockers may precipitate bradycardia, hypotension, heart block, HF, and bronchoconstriction

Question 22

These medications should never be stopped abruptly

Answer 22

.

Question 23

Beta-Blocking Agents: Nursing Implications

Answer 23

Patients should report the following to their physician:

Weight gain of more than 2 pounds (1 kg) within a week
Edema of the feet or ankles
Shortness of breath
Excessive fatigue or weakness
Syncope or dizziness

Question 24

antagonists vs agonists

Answer 24

agnoist drugs stim the SNS because the bind to the receptor and cause a response.

antagonists inhibit or block stimulation of the SNS

Question 25

a-BLOCKERS at the a receptors leads to

Answer 25

vasodilations, decrease in BP, miosis, and supressed ejaculation

Question 26

oxytocics

Answer 26

drugs given postpartum and postabortion to control bleeding

Question 27

beta (b1) blockers result in

Answer 27

(LOCATED IN THE HEART*****)

REDUCES HEART RATE, SLOWS CONDUCTION THROUGH AV NODE, PROLONGS SA NODE, AND CONTRACTILITY.

so in short,decreases conduction, contraciliity, and heart rate

Question 28

SOME B-BLOCKERS ARE MAINLY USED TO TREAT

Answer 28

ANGINA

Question 29

VASODILATION OF BLOOD VESSELS WITH THE A-BLOCKERS RESULT IN

Answer 29

A DROP IN bp and increase in urinary flow rates.

Question 30

blocking b2 receptors leads

Answer 30

to decrease in in bronc smooth muscle relaxation, or broncoconsrtiction

Question 31

8. Beta blockers are used in the treatment of

Answer 31

HYPERTENSION, DYSRYTHMIAS and GLAUCOMA, HEART RATE AND MIGRANES

Question 32

9. Rebound hypertension with chest pain can be seen if

Answer 32

STOPPED ABRUTPLY MEDS

Question 33

Shortness of breath, pitting edema, syncope, dizziness, fatigue and weakness are symptoms of

Answer 33

CONGESTIVE HEART FAILURE

Question 34

with a-blockers the predominate response is

Answer 34

vasodilation. this response is due to blocking of the a-adrenergiceffect of vasoconstriction, which results in blood vessel dialtion

Question 35

vasodilation of blood vessel with the a-blockers will result in

Answer 35

BP drop and reduction in urinary obstruction that may lead to increase urinar flow rates.