Peripheral Nervous System Drugs

Question 1

Sympathomimetic/Adrenergic Agonist drugs function:

Answer 1

Stimulates the SNS
1) Directly activate adrenergic receptors
OR
2) Indirectly activate adrenergic receptors by ↑ing release of NE from nerve terminals

1) HTN (alpha2)
2) asthma (beta2)
2) Pre-term labor (beta2)
3) cardiac arrest (beta1)
4) nasal congestion (alpha1)

Question 2

Sympathomimetic/Adrenergic Agonist drugs act on which receptors?

Answer 2

𝛂lpha and 𝛃eta receptors

Ignore alpha2

Question 3

Sympathomimetic/Adrenergic Agonist Prototype:

Answer 3

Epinephrine (Catecholamine)

Question 4

Epinephrine MOA:

Answer 4

Activates:

1) Alpha1 receptors (vasoconstriction)
2) Alpha2 receptors ( ↑ release of NE)
3) Beta1 receptors (↑ HR, contractility, & AV conduction velocity)
4) Beta2 receptors (bronchodilation)

Question 5

Epinephrine is primarily used for what type of situations? Other therapeutic uses?

Answer 5

PRIMARILY USED FOR EMERGENCIES!
Life-saving Drugs

1) Cardiac arrest (beta1)
2) Anaphylaxis (↑ BP, alpha1)
3) Hemostasis (alpha1)
4) Bronchodilation (beta2)
5) Vasoconstriction (alpha1)

Question 6

Epinephrine ADRs:

Answer 6

1) Hypertensive crisis (vasoconstriction)
2) Dysrhythmias
3) Angina
4) Necrosis from extravasation
5) Hyperglycemia (exacerbated in DM pts)

Question 7

Epinephrine Nursing Considerations & Contraindications:

Answer 7

NCs:

1) Monitor pt’s cardiac status
- can use Beta-blocker (Metoprolol) to reduce cardiac ADRs
2) Monitor BP
- can use
3) Monitor blood glucose levels in DM pts

Contraindicated for use in pts with:

1) cardiac issues (dysrhythmias)
2) HTN

Question 8

Anti-Adrenergic/Adrenergic Antagonist drugs function:

Answer 8

Blocks the SNS

Directly or Indirectly ↓ release of NE from nerve terminals

Question 9

Antiadrenergic/Adrenergic Antagonist drugs act on which receptors?

Answer 9

𝛂lpha and 𝛃eta receptors

Question 10

Antiadrenergic/Adrenergic Antagonist drugs used for (Disorders, Location, Receptor, and Effect):

Answer 10

Used for HTN, PV disorders, and CHF

1) Heart (𝛃1) –> ↓HR, ↓ contractility (force), ↓ conduction
2) Lungs (𝛃2) –> bronchoconstriction
3) Blood vessels (𝛂1) –> Vasodilation (↓ BP)

MOST WIDELY PRESCRIBED CLASS OF ANS Drugs

Question 11

Alpha1 Receptor Antiadrenergic/Adrenergic Antagonist Prototype:

Answer 11

Prazosin (Minipress)

Question 12

Prazosin (Minipress) MOA:

Answer 12

Blocks the SNS
Selective blockade of alpha1 receptors
1) Vasodilation of arterioles & veins (↓ BP)
2) Contraction of detrusor muscle & Relaxation of bladder sphincters & prostatic capsule (↑ urinary outflow)

Question 13

Prazosin (Minipress) Therapeutic Uses:

Answer 13

1) Essential HTN (vasodilation, ↓ BP)
- NOT as a monotherapy
2) BPH (↑ urinary outflow)

Question 14

Prazosin (Minipress) Therapeutic ADRs:

Answer 14

1) 1st dose: orthostatic hypotension
2) dizziness, lightheadedness
3) weakness
4) headache
5) Reflex tachycardia
6) Nasal congestion

Question 15

Prazosin (Minipress) Nursing Considerations:

Answer 15

1) Monitor BP & HR before and after administration
2) Instruct pt to stand or sit up slowly, or take 1st dose before bed to minimize effects of postural hypotension
(1st dose should also be small)

Question 16

Beta Receptor Antiadrenergic/Adrenergic Antagonist Prototype:

Answer 16

Propranolol (Inderal LA)

Question 17

Propranolol (Inderal LA) MOA:

Answer 17

Blocks the SNS
Non-selective blockade of beta1 and beta2 receptors
1) ↓ HR, Contractility, & electrical conduction resulting in decreased Cardiac output (beta1)
2) Suppress renin secretion (beta1)
3) Bronchoconstriction of lungs (beta2)
4) Vasoconstriction of blood vessels (beta2)
5) ↓ glycogenolysis (beta2)

(AKA Beta-blocker)

Question 18

Propranolol (Inderal LA) Therapeutic Uses:

Answer 18

1) HTN
2) Angina
3) Dysrhythmias
4) MI

“lol in your heart”

Question 19

Propranolol (Inderal LA) ADRs:

Answer 19

1) Bradycardia
2) AV heart block
3) HF
4) Rebound cardiac excitation
5) Bronchoconstriction
6) Inhibition of glycogenolysis
-More likely in pts w/ DM to become hypoglycemic if med abruptly stopped
⧫ CNS Effects

Question 20

Propranolol (Inderal LA) Nursing Considerations:

Answer 20

1) Monitor BP & HR before & after administration
- orthostatic BP (supine & standing)
2) Monitor heart with ECG
3) Pts w/ DM: Monitor blood glucose levels more frequently; S/S of hypoglycemia may or may not present

Caution/Contraindicated for pts with:

1) HF
2) Asthma
3) Diabetes
4) Depression
5) Congruent use w/ CCB

Question 21

Cholinergic/Parasympathomimetic/Muscarinic Agonist drugs function:

Answer 21

Stimulates the PsNS
1) Directly stimulates cholinergic receptors
OR
2) Indirectly stimulates cholinergic receptors by inhibiting acetylcholinesterase (↑ ACh)
- treat urinary retention
-treat glaucoma

Question 22

Cholinergic/Parasympathomimetic/Muscarinic Agonist drugs act on which receptors?

Answer 22

Muscarinic and Nicotinic receptors

Question 23

Cholinergic/Parasympathomimetic/Muscarinic Agonist Prototype:

Answer 23

Bethanechol (Urecholine)

Question 24

Bethanechol (Urecholine) MOA:

Answer 24

Stimulates PsNS
Directly bind & activate muscarinic receptors
1) Stimulates smooth muscle contraction in GI and Urinary system

Question 25

Bethanechol (Urecholine) Therapeutic Uses:

Answer 25

1) Urinary retention (stimulates contraction of smooth muscles)
- Used postpartum or NON-OBSTRUCTIVE urinary retention

Question 26

Bethanechol (Urecholine) ADRs:

Answer 26

1) GI Distress (ab. discomfort, N/V/D)
2) Hypotension
3) Bradycardia
4) Salivation
5) flushing
6) sweating

Question 27

Bethanechol (Urecholine) Nursing Considerations:

Answer 27

1) Give 1 hr before or 2 hrs after a meal to reduce GI distress
2) Monitor I&O

Contraindicated for pts with:

1) Urinary Obstructions (BPH)**
2) Bowel Obstructions
3) Asthma

Question 28

Anticholinergic/Muscarinic Antagonist drugs function:

Answer 28

Blocks the PsNS
Directly blocks ACh at muscarinic receptors
-Induces SEs of SNS

1) Dry secretions (block vasodilation)
2) Treat asthma (block bronchoconstriction)
3) Pupils (blocks constriction–dilation)

Question 29

Anticholinergic/Muscarinic Antagonist drugs receptors:

Answer 29

Muscarinic (& nicotinic)

Question 30

Anticholinergic/Muscarinic Antagonist Prototype:

Answer 30

Atropine

Question 31

Atropine MOA:

Answer 31

Blocks PsNS
Blockade of ACh at muscarinic receptors on the heart, exocrine glands, smooth muscles, & eyes
-induces Sxs of SNS
1) ↑ HR
2) Dilation of pupils (mydriasis)
3) Suppress secretions (salivary, bronchial, sweat, stomach acid)
4) Relaxation of smooth muscles (bronchi, bladder, GI)
-no effect on vascular smooth muscles (no PsNS innervation in blood vessels)

Question 32

Atropine Therapeutic Uses:

Answer 32

1) ↑ HR in Bradycardia
2) Eye exams (pupil dilation)
3) IBS
4) Suppress secretions during surgical procedures

Question 33

Atropine ADRs:

Answer 33

1) drowsiness
2) blurred vision, photophobia
↑ed intraocular pressure
3) Tachycardia
4) dry mouth
5) constipation
6) urinary retention
7) anhidrosis (Can’t sweat)

Question 34

Atropine Nursing Considerations:

Answer 34

1) Monitor HR before & after administration
2) Be able to Differentiate overdose from psychosis!
- DON’T administer an anti-psychotic (can make it worse)
3) Instruct pt to sip water or sugar-free chew gum to moisten mouth & aid with swallowing
4) Instruct pt to wear sunglasses and avoid hazardous activities due to blurred vision
5) Instruct pt to void before taking med to reduce urinary retention
6) Instruct pt to increase fluid & fiber intake to reduce constipation
7) Instruct pt to avoid vigorous exercise to reduce risk of hyperthermia (anhidrosis)

Contraindicated in pts with:
1) Glaucoma

Question 35

Atropine Overdose Signs & Symptoms:

Answer 35

Hot as hades
-Blockade of sweat glands, fever (hyperthermia)
Red as a Beet
-Flushed face, tachycardia
Blind as a bat
-Pupils unable to constrict in bright light
Dry as a bone
-Salivary glands blocked, decreased secretions, thirsty
Mad as a hatter
-Delirium, Confusion, Agitation, hallucinations

Question 36

What is the Antidote for an Atropine overdose?

Answer 36

Physostigmine
-acetylcholinesterase inhibitor

(Will also give activated charcoal)