Neuropharmacology Part 1

short duration

NO oral form (given parenterally)

Doesn’t cross BBB - good for pregnancy 🙂

catecholamines

what are the examples of catecholamines

epinephrine

norepinephrine (levophed)

Isoproterenol (Isuprel)

dopamine

dobutamine

longer duration

oral form availavle

can cross BBB - ☹

non-catecholamines

give me the examples of non-catecholamines

phenylephrine (neo-synephrine), albuterol (ventolin), ephedrine

A-2 activation

activation leads to inhibition of _________ release and is of little clinical significance in the periphery. It is much more important in the _____.

Therapeutic uses in the ____.

• reduction of ________ outflow to heart and vessels

• relief of _____ ______

norepinephrine, CN, sympathetic, severe pain

adrenergic antagonists

with one exception, all produce what?

reversible (competitive) blockade

most adrenergic antagonists are more _______ than adrenergic agonists

selective

Most AE is potentiation of reflex tachycardia that can occur in response to blockade of _______-

a-1 receptors

what are the two adrenergic antagonists

alpha-adrenergic blocking agents, beta-adrenergic blocking agents

very selective to blocking beta 1, a (2nd gen) cardioselective beta blocker

(metoprolol) Lopressor

a 1st gen non-selective beta blocker

propranolol (inderal)

a 3rd gen beta blocker with alpha-1acions

carvedilol (coreg)

increased synthesis of T

impact on receptor activation

increase

decreased synthesis of T

impact on receptor activation

decrease

synthesis of “super” T

impact on receptor activation

increase

reduced storage of T

impact on receptor activation

decrease

promotion of T release

impact on receptor activation

increase

inhibition of T release

impact on receptor activation

decrease

direct receptor activation

impact on receptor activation

increase

enhanced response to T

impact on receptor activation

increased

blockade of T binding

impact on receptor activation

increased

blockade of T reuptake

impact on receptor activation

increase

inhibition of T breakdown

impact on receptor activation

increase

defined as producing an effect equivalent to that produced by the natural transmitter that acts on a particular receptor

receptor activation

functions of parasympathetic nervous system

• _____ of heart rate​

• _____ gastric secretion​

• _____ of the bladder​

• _____ of the bowel​

• ______ of the eye for near vision​

• Pupil _______

• Bronchial smooth muscle ______

slowing, increased, emptying, emptying, focusing, constriction, constriction.

If it works on muscarinic or nicotinic

parasympathetic

functions of the sympathetic nervous system

3 main functions

regulates cardiovascular system

body temperature regulation

acute stress response implementation

functions of the sympathetic nervous system

achieves 3 homeostatic objectives

maintains blood flow to brain, redistributes blood flow during exercise, compensation of blood loss through vasoconstriction

Something that needs both the help of the parasympathetic and sympathetic innervation

the male genitals

adrenergic receptors can be activated by endogenous:

epinephrine, norepinephrine, dopamine

contraction of the radial muscle of iris causes mydriasis (increased pupil size)

constriction of arterioles, veins, prostatic capsule, and bladder (trigone and sphincter)

alpha 1

on the presynaptic nerve terminal,

inhibition of transmitter release

alpha 2

on the heart and kidneys

increased rate, force of contraction, AV conduction velocity, release of renin

beta 1

dilation of the arterioles, heart, lung, skeletal muscle

dilation of the bronchi

relaxation of uterus

glycogenolysis of liver

enhanced contraction, glycogenolysis of skeletal muscle

beta 2

on the kidney,

dilation of kidney vasculature

dopamine

neurotransmitter: norepinephrine

location of action?

a1, a2, b1

neurotransmitter: epinephrine

location of action?

a1, a2, b1, b2

neurotransmitter: dopamine

location of action? dopamine, a1, b1

dopamine

neurotransmitter: acetylcholine

location of action?

nicotinic and muscarinic receptors (cholinergic)

Sympathetic = Adrenergic = Sympathetic Agonists =

sympathomimetic

Parasympathetic = Cholinergic = Parasympathetic Agonists =

parasympathomimetic

• drug that block/decrease sympathetic response​

​

sympatholytic

drug that block/decrease parasympathetic response​

parasympatholytic

mechanism of adrenergic receptor activation need what

norepinephrine or direct receptor binding

true or false

most adrenergic agonists activate more than one receptor type

true

what are the receptors of epinephrine (adrenaline)

A1, A2, B1, B2

Therapeutic applications​

• Anaphylaxis​

• Vasoconstriction​

• Hemostasis​

• Nasal de-congestion​

• Adjunct to local anesthesia​

  Management of cardiac arrest, including

  • Ventricular Fibrillation

  • pulseless Ventricular Tachycardia

  • Pulseless Electrical Activity

  • Asystole​

mydriasis

epinephrine

• Adverse effects​

• CV – hypertension (a1), dysrhythmia (b1) , angina pectoris (b1) ​

• Necrosis secondary to IV line extravasation (give ɑ-1 antagonist phentolamine) - so much blood shunted to that extremity ​

• Hyperglycemia (B2)​

epinephrine

• Continually monitor vital signs (because of BP and HR) and access sites with IV formulation​

• Increased insulin therapy needed if used in patients with existing diabetes​

• Caution with high-risk patients and numerous medication interactions​

epinephrine

what are the receptors for norepinephrine (levophed)

A1, A2, B1

Therapeutic applications​

• Increased heart rate, contractility, & enhanced impulse conduction​

• Used in conditions such as heart failure, shock, AV heart block, & cardiac arrest​

norepinephrine

Adverse effects​

• Altered heart rate (e.g. tachycardia) & dysrhythmias​

• Angina pectoris​

• Local necrosis – from alpha 1 , rest from beta 1

norepinephrine

• Monitor cardiovascular status, including vital signs and electrocardiogram, closely while administering via continuous infusion​

• Assess access sites and extremities frequently to monitor for distal ischemia​

norepinephrine

DOPAMINE

Parenteral adrenergic agonist class medication with dose-dependent effects​

• A small dose (0.5-3 mcg/kg/min) stimulates dopamine receptors to produce renal vasodilation – to perfuse kidneys ​

• Medium dose (3-10) activates dopamine and ___ receptors ​

• Large dose (10-20) activates dopamine, ___, and ____ receptors​

b1, b1 and a1

Adverse effects​

• CV - Tachycardia, dysrhythmias, anginal pain​

• Necrosis from localized vasoconstriction​

dopamine

DOPAMINE

Therapeutic applications​

• Medium dose is effective for increasing ______ in the treatment of shock and heart failure by_____ contractility, cardiac output, and renal perfusion​

cardiac performance, increasing

Nursing considerations​

• Monitor cardiovascular status, including vital signs and electrocardiogram, closely while administering via continuous infusion​

• Monitor urine output/I&Os closely to monitor the status of renal perfusion​

• Stop infusion and administer phentolamine if extravasation (a1 antagonist) occurs

dopamine

Parenteral adrenergic agonist class medication with actions at 𝛃1 receptors to increase myocardial contractility and stroke volume​

dobutamine

chemical class of dobutamine

catecholamine

therapeutic applications of dobutamine

congestive heart failure

drug interactions of dobutamine

monoamine oxidase inhibitors, tricyclic antidepressants, and certain general anesthetics

nursing considerations for dobutamine

monitor BP/EKG, titrate based on weight

Albuterol (Ventolin) - Adrenergic agonist class medication with actions usually selective at

B2 receptors but can also affect B1 if given at high dose

for short acting bronchodilation for obstructive pulmonary conditions, such as asthma and COPD​

albuterol

what are the adverse effects of albuterol

hyperglycemia from hepatic glycogenolysis in patients with diabetes

tremors due to increased muscle contraction

• Monitor for cardioselective activity from increased HR​

• Monitor glucose if patient has DMI/DMII​

• Provide education on proper inhalation technique if used as a PRN Short ActingBeta Agonist and assess home use​

albuterol

Prazosin (minipress)

Adrenergic antagonist class medication with actions selective for

A1

what is prazosin used for

high blood pressure in essential hypertension and pheochromocytoma

what are the adverse effects of prazosin

orthostatic hypotension, reflex tachycardia, nasal decongestion, inhibition of ejaculation, sodium retention and increased blood volume

nursing considerations for prazosin

obtain BP and HR before administering med,

educate patients on changing position after starting med

can be given with or without food

monitor for higher risk of falls due to orthostatic hypotension

• Adrenergic antagonist class medication with actions selective for ____ receptors in the bladder neck for treatment of BPH​

A1 - tamsulosin (flomax)

adverse effects of tamsulosin (flomax)

headache and dizziness, abnormal ejaculation

nursing considerations of tamsulosin

• Often used in patients who are on antihypertensives and agents for ED, so monitor blood pressure​

• Evaluate urinary habits to monitor for response, particularly for nocturia, frequency, hesitancy, urgency, force of stream, etc.

B-1 Blocker Medications

Enteral and parenteral adrenergic antagonist class medication​

• Three generations​

• 1st: nonselective -

• 2nd: Cardioselective -

• 3rd: Beta blocker with vasodilating actions -

propanalol, metoprolol, cervedilol

• Therapeutic applications occur on mostly 𝛃-1​

for beta blockers

angina pectoris, HTN, dysrhythmias, MI, HF, hyperthyroid, stage fright (propanolol), glaucoma.

Adverse effects occur on both

: Bradycardia, reduced Cardiac Output, Heart Failure, AV heart block, reduced cardiac excitation ​

: Bronchoconstriction, hypoglycemia​, Bradycardia & respiratory distress in neonates​

B1 and B2

• Monitor heart rhythm, blood pressure & heart rate prior to administration​

• Monitor for respiratory distress if used in patients with obstructive respiratory conditions, as well as myocardial suppression-related HF​

• Educate patients on all possible signs of hypoglycemia due to symptom masking​

b1 blocker meds,

• Indirect-acting antiadrenergic class medication administered via transdermal patch or PO administration for hypertension​

clonidine (catapress)

under other trade names used for ADHD and severe pain​

clonidine

• MOA: Activates ɑ-2 receptors in the CNS to reduce sympathetic outflow to blood vessels and heart​

clonidine (catapress)

adverse effects of clonidine

• Drowsiness​

• Xerostomia – dry mouth ​

• Rebound hypertension​

• Potential for abuse due to subjective euphoria​

• Potential for fetal harm – not on pregnant women​

nursing considerations for clodnine

• Monitor blood pressure (rebound htn) and heart rate prior to administration​

• Educate patients on using gum, hard candy, and staying hydrated to limit xerostomia​

• Warn patients on rebound hypertension​

• Assess for history of illicit drug & opioid abuse

what is a rule for clonidine (catapress)

never use long term, only in emergency situations

how often is a clonidine patch changed

every 7 days