Peripheral Nervous System Drugs Flashcards
Sympathomimetic/Adrenergic Agonist drugs function:
Stimulates the SNS
1) Directly activate adrenergic receptors
OR
2) Indirectly activate adrenergic receptors by โing 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)
Sympathomimetic/Adrenergic Agonist drugs act on which receptors?
๐lpha and ๐eta receptors
Ignore alpha2
Sympathomimetic/Adrenergic Agonist Prototype:
Epinephrine (Catecholamine)
Epinephrine MOA:
Activates:
1) Alpha1 receptors (vasoconstriction)
2) Alpha2 receptors ( โ release of NE)
3) Beta1 receptors (โ HR, contractility, & AV conduction velocity)
4) Beta2 receptors (bronchodilation)
Epinephrine is primarily used for what type of situations? Other therapeutic uses?
PRIMARILY USED FOR EMERGENCIES!
Life-saving Drugs
1) Cardiac arrest (beta1)
2) Anaphylaxis (โ BP, alpha1)
3) Hemostasis (alpha1)
4) Bronchodilation (beta2)
5) Vasoconstriction (alpha1)
Epinephrine ADRs:
1) Hypertensive crisis (vasoconstriction)
2) Dysrhythmias
3) Angina
4) Necrosis from extravasation
5) Hyperglycemia (exacerbated in DM pts)
Epinephrine Nursing Considerations & Contraindications:
NCs:
1) Monitor ptโs 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
Anti-Adrenergic/Adrenergic Antagonist drugs function:
Blocks the SNS
Directly or Indirectly โ release of NE from nerve terminals
Antiadrenergic/Adrenergic Antagonist drugs act on which receptors?
๐lpha and ๐eta receptors
Antiadrenergic/Adrenergic Antagonist drugs used for (Disorders, Location, Receptor, and Effect):
Used for HTN, PV disorders, and CHF
1) Heart (๐1) โ> โHR, โ contractility (force), โ conduction
2) Lungs (๐2) โ> bronchoconstriction
3) Blood vessels (๐1) โ> Vasodilation (โ BP)
MOST WIDELY PRESCRIBED CLASS OF ANS Drugs
Alpha1 Receptor Antiadrenergic/Adrenergic Antagonist Prototype:
Prazosin (Minipress)
Prazosin (Minipress) MOA:
Blocks the SNS
Selective blockade of alpha1 receptors
1) Vasodilation of arterioles & veins (โ BP)
2) Contraction of detrusor muscle & Relaxation of bladder sphincters & prostatic capsule (โ urinary outflow)
Prazosin (Minipress) Therapeutic Uses:
1) Essential HTN (vasodilation, โ BP)
- NOT as a monotherapy
2) BPH (โ urinary outflow)
Prazosin (Minipress) Therapeutic ADRs:
1) 1st dose: orthostatic hypotension
2) dizziness, lightheadedness
3) weakness
4) headache
5) Reflex tachycardia
6) Nasal congestion
Prazosin (Minipress) Nursing Considerations:
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)
Beta Receptor Antiadrenergic/Adrenergic Antagonist Prototype:
Propranolol (Inderal LA)
Propranolol (Inderal LA) MOA:
Blocks the SNS
Non-selective blockade of beta1 and beta2 receptors
1) โ 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) โ glycogenolysis (beta2)
(AKA Beta-blocker)
Propranolol (Inderal LA) Therapeutic Uses:
1) HTN
2) Angina
3) Dysrhythmias
4) MI
โlol in your heartโ
Propranolol (Inderal LA) ADRs:
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
โงซ CNS Effects
Propranolol (Inderal LA) Nursing Considerations:
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
Cholinergic/Parasympathomimetic/Muscarinic Agonist drugs function:
Stimulates the PsNS
1) Directly stimulates cholinergic receptors
OR
2) Indirectly stimulates cholinergic receptors by inhibiting acetylcholinesterase (โ ACh)
- treat urinary retention
-treat glaucoma
Cholinergic/Parasympathomimetic/Muscarinic Agonist drugs act on which receptors?
Muscarinic and Nicotinic receptors
Cholinergic/Parasympathomimetic/Muscarinic Agonist Prototype:
Bethanechol (Urecholine)
Bethanechol (Urecholine) MOA:
Stimulates PsNS
Directly bind & activate muscarinic receptors
1) Stimulates smooth muscle contraction in GI and Urinary system
Bethanechol (Urecholine) Therapeutic Uses:
1) Urinary retention (stimulates contraction of smooth muscles)
- Used postpartum or NON-OBSTRUCTIVE urinary retention
Bethanechol (Urecholine) ADRs:
1) GI Distress (ab. discomfort, N/V/D)
2) Hypotension
3) Bradycardia
4) Salivation
5) flushing
6) sweating
Bethanechol (Urecholine) Nursing Considerations:
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
Anticholinergic/Muscarinic Antagonist drugs function:
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 constrictionโdilation)
Anticholinergic/Muscarinic Antagonist drugs receptors:
Muscarinic (& nicotinic)
Anticholinergic/Muscarinic Antagonist Prototype:
Atropine
Atropine MOA:
Blocks PsNS
Blockade of ACh at muscarinic receptors on the heart, exocrine glands, smooth muscles, & eyes
-induces Sxs of SNS
1) โ 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)
Atropine Therapeutic Uses:
1) โ HR in Bradycardia
2) Eye exams (pupil dilation)
3) IBS
4) Suppress secretions during surgical procedures
Atropine ADRs:
1) drowsiness
2) blurred vision, photophobia
โed intraocular pressure
3) Tachycardia
4) dry mouth
5) constipation
6) urinary retention
7) anhidrosis (Canโt sweat)
Atropine Nursing Considerations:
1) Monitor HR before & after administration
2) Be able to Differentiate overdose from psychosis!
- DONโT 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
Atropine Overdose Signs & Symptoms:
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
What is the Antidote for an Atropine overdose?
Physostigmine
-acetylcholinesterase inhibitor
(Will also give activated charcoal)
