sympathetic nervous system (adrenergic)

Question 1

the sympathetic nervous system (adrenergic) is stimulated by…

Answer 1

physical or emotional stress

Question 2

physiological responses when the SNS is activated include

Answer 2

• increased HR, arterial blood pressure, and cardiac output
• increased blood glucose (breakdown of muscle glycogen prn)
• increased mental activity/clear thinking
• pupil dilation
• increased rate of cellular metabolism
• increased blood flow to brain, heart, and skeletal muscle
• relaxation of smooth muscle of urinary bladder

Question 3

what are the 3 primary adrenergic neurotransmitters

Answer 3

• norepinephrine
• epinephrine (adrenaline)
• dopamine

Question 4

norepinephrine, epinephrine, and dopamine are all…

Answer 4

endogenous “catecholamines”

Question 5

define catecholamines

Answer 5

• neurotransmitters when they are produced in the sympathetic nervous system and brain, and circulating hormones when synthesized in the adrenal medulla
• can produce a sympathomimetic response

Question 6

describe sympathomimetic

Answer 6

mimics the sympathetic system

Question 7

where is norepinephrine synthesized?

Answer 7

adrenergic nerve endings (released when nerve endings are stimulated)

Question 8

describe the action of norepinephrine

Answer 8

• intense/brief/most → reuptake for reuse
• does its job quickly in the sympathetic nervous system, then gets put away for later

Question 9

what drugs prevent the reuptake of norepinephrine

Answer 9

cocaine and tricyclic antidepressants

Question 10

what enzymes assist with reuptake and metabolism of norepinephrine and epinephrine

Answer 10

• monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT) metabolize remaining portion in tissue and bloodstream (via liver)
• effects of epinephrine last longer

Question 11

what is required in the diet to produce norepinephrine?

Answer 11

• tyrosine
• found in dairy, cheese, beef, soybeans, nuts, and eggs

Question 12

where is epinephrine produced?

Answer 12

produced by both adrenal glands and a small number or neurons in the medulla oblongata where it acts as a neurotransmitter involved in regulating visceral functions (e.g. respiration)

Question 13

describe how epinephrine is an important emergency medication

Answer 13

• strengthens myocardial contraction and used in the treatment of anaphylaxis
• in anaphylaxis (narrowing of the airway) it causes veins to constrict (pump more blood) and relaxes the respiratory muscles

Question 14

where is dopamine found and how does it act?

Answer 14

• found in brain, blood vessels of the kidneys, and other viscera
• acts on the BP and HR
• pleasure/rewards system and attention/problem solving in frontal lobe
• affects are dose dependent

Question 15

low dose dopamine is used to treat…

Answer 15

• acute renal failure
• increases renal blood flow

Question 16

what is a higher dose of dopamine used for?

Answer 16

increase blood pressure

Question 17

dopamine can be used to treat:

Answer 17

• hypotension
• shock
• myocardial infarction
• trauma
• renal failure

Question 18

where are Alpha₁ receptors located

Answer 18

located primarily in smooth muscle in blood vessels, GI and GU tracts

Question 19

what happens when Alpha₁ receptors are stimulated

Answer 19

• production of muscle contraction / vasoconstriction / mydriasis (dilated pupils)
• gastrointestinal/bladder sphincter contraction (urinary retention)

-

Question 20

what happens when Alpha₁ receptors are inhibited

Answer 20

• relax vascular smooth muscle / cause vasodilation
• decrease BP and treat BPH

Question 21

where are alpha₂ receptors located

Answer 21

located in the brain and pancreatic B cells

Question 22

what happens when alpha₂ receptors are stimulated

Answer 22

• inhibits norepinephrine → have antiadrenergic effect
• inhibits insulin release

Question 23

what happens when alpha₂ receptors are inhibited?

Answer 23

• stimulates norepinephrine - have adrenergic effect
• stimulates insulin release

Question 24

where are beta₁ receptors located

Answer 24

primarily in cardiac cells

Question 25

what happens when beta₁ receptors are stimulated

Answer 25

increase HR and force of contraction

Question 26

what happens when beta₁ receptors are inhibited

Answer 26

- decrease HR and force of contraction - "beta adrenergic blockers" (BP medication) work to lower BP and control heart rate by blocking these receptors

Question 27

beta adrenergic blockers are used in the treatment of…

Answer 27

- HTN - dysrhythmias - HF - MI - narrow angle glaucoma

Question 28

where are beta₂ receptors located

Answer 28

located primarily in smooth muscle of the lungs/skeletal/detrusor and uterine muscles

Question 29

what happens when beta₂ receptors are stimulated

Answer 29

relaxation of smooth muscles of the lungs = bronchodilation

Question 30

what happens when beta₂ receptors are inhibited

Answer 30

bronchoconstriction

Question 31

what receptor is the site of action for respiratory and asthma medications

Answer 31

beta₂ receptors

Question 32

name the adrenergic drug classifications

Answer 32

- adrenergic - sympathomimetic / adrenergic agonist - sympatholytic / adrenergic antagonist - adrenergic blocker - alpha 1 and 2 receptor (selective vs nonselective) - beta 1 and 2 receptor (selective vs nonselective)

Question 33

what drugs mimic the effect of norepinephrine

Answer 33

- sympatho**mimetics** - adrenergic a**go**nists

Question 34

what drugs block the effects of norepinephrine

Answer 34

- sympatho**lytics** - adrenergic blockers AKA adrenergic **antago**nists

Question 35

**sympathomimetic treatment based on receptor site activation** Alpha₁

Answer 35

Tx of nasal congestion, hypotension, cause dilation of pupils (for glaucoma)

Question 36

**sympathomimetic treatment based on receptor site activation** alpha₂

Answer 36

Tx of hypertension (inhibits norepinephrine, decreases BP)

Question 37

**sympathomimetic treatment based on receptor site activation** Beta₁

Answer 37

tx of cardiac arrest, HF, shock

Question 38

**sympathomimetic treatment based on receptor site activation** beta₂

Answer 38

tx of asthma and premature labor contractions

Question 39

explain the difference between selective and nonselective medications

Answer 39

**selective medications** - act on a specific receptor site - induces the normally occurring action of the receptor site - less side effects **nonselective medications** - act on more than one type of receptor site - more broad range of effects - more side effects

Question 40

Describe phenylephrine

Answer 40

- stimulates A₁ to constrict - increases BP - common in allergy, decongestant preparations bc it constricts nasal vessels to decrease congestion

Question 41

what should you monitor when giving low dose dopamine

Answer 41

urine output (bc its a renal dose)

Question 42

what should you monitor when giving a high dose of dopamine

Answer 42

monitor BP (bc its a cardiac dose)

Question 43

what receptors does norepinephrine stimulate

Answer 43

A₁, A₂, and B₁

Question 44

what should you be concerned about when a pt is hypertensive and is given an epi pen

Answer 44

epi pens are nonselective and can cause BP issues when used with hypertension

Question 45

what is epinephrine used for

Answer 45

- allergic reaction/anaphylaxis - ACLS medication

Question 46

describe midodrine

Answer 46

- alpha adrenergic agonist - for treatment of orthostatic hypotension

Question 47

describe albuterol

Answer 47

- selective B₂ adrenergic agonist - bronchodilation

Question 48

describe isoproterenol

Answer 48

**-nonselective** B₁ and B₂ adrenergic agonist - increased HR (B₁) and bronchodilation (B₂) - not safe for pts with tachycardia or hypertension

Question 49

name some side effects of sympathomimetics

Answer 49

- tachycardia, dysrhythmias, chest pain - HTN - CNS excitement, nervousness, restlessness - dry mouth - N/V - HA - dysuria

Question 50

what are some nursing concerns related to the sympathomimetic side effect… tachycardia, dysrhythmias, CP

Answer 50

- VS - telemetry - nitrates (med that treats CP - potent vasodilators)

Question 51

what are some nursing concerns related to the sympathomimetic side effect… HTN

Answer 51

- VS - low sodium diet - renal function - fluid intake

Question 52

what are some nursing concerns related to the sympathomimetic side effect… CNS excitement, nervousness, restlessness

Answer 52

relaxation techniques

Question 53

what are some nursing concerns related to the sympathomimetic side effect… dry mouth

Answer 53

- fluid provision - oral hygiene - ice chips

Question 54

what are some nursing concerns related to the sympathomimetic side effect… nausea and vomiting

Answer 54

- ginger ale - antiemetic - fluid volume status (careful of dehydration)

Question 55

what are some nursing concerns related to the sympathomimetic side effect… headache

Answer 55

- lighting - quiet environment - pain meds

Question 56

what are some nursing concerns related to the sympathomimetic side effect… dysuria

Answer 56

- I&O - urine assessment - increase fluids to flush (if not on fluid restriction)

Question 57

what are some contraindications/cautions r/t sympathomimetics

Answer 57

- pheochromocytoma - tachy-arrhythmias - CV disease/PVD - thyroid disease - hypovolemia - renal or hepatic impairment - drug interactions

Question 58

describe pheochromocytoma

Answer 58

a rare neoplasm that secrets catecholamines and is usually found in the adrenal medulla

Question 59

what are the signs/symptoms and treatment of pheochromocytoma

Answer 59

- Sx: HTN, headache, heart palpitations, sweating - Tx: medication and often times surgery

Question 60

describe tachy-arrhythmias

Answer 60

fast, irregular heart rhythms

Question 61

how can thyroid disease contraindicate sympathomimetics

Answer 61

- hyperthyroid - the thyroid hormone increases target cell responsiveness to catecholamines

Question 62

how can hypovolemia contraindicate sympthaomimetics

Answer 62

vasoconstrict a vascular system with no blood volume

Question 63

what types of drugs do sympathomimetics interact with

Answer 63

- **TCA**s: impairs reuptake of norepinephrine - **MAOI**s: inhibits liver metabolism or norepi/epi - **herbals** - **OTCs**