Adrenergic Agonists

Question 1

List order of synthesis to get norepi, epi, dopamine, and isoproterenol starting with the initial compound they are all formed from.

Answer 1

L-Tyrosine –> L-Dopa –> Dopamine –> Norepinephrine –> Epinephrine –> Isoproterenol

Question 2

Where are B3 receptors found?

Answer 2

Adipose (lipolysis), skeletal muscle (thermogenesis), gallbladder, urinary bladder (relax), CNS

Question 3

Order the following in terms of smallest group on amine to largest. Isoproterenol, norepinephrine, epinephrine

Answer 3

Norepinephrine, epinephrine, isoproterenol

Question 4

What receptors do blood vessels to skeletal muscle have?

Answer 4

a1 and B2

Question 5

Why do local anesthetics contain epinephrine?

Answer 5

To achieve local vasoconstriction (via a1) to keep the anesthetic locally for a longer duration

Question 6

What is the dominant receptor on veins?

Answer 6

a1 - constriction (storing blood)

Question 7

How much epinephrine is released per day in a normal body?

Answer 7

20-100 ug

Question 8

What is the effect of epinephrine on immune system?
A. Up- regulate
B. Down- regulate

Answer 8

B

Question 9

Does dopamine increase contractility (stroke volume) or heart rate more? What does this minimize?

Answer 9

Contractility (stroke volume)

This minimizes oxygen demand/consumption

Question 10

Does dopamine cross the blood-brain barrier?

Answer 10

No

Question 11

What drug can you give to people with Parkinson’s disease?

Answer 11

L-DOPA - gets converted to dopamine in nerve terminals

Question 12

What is the rate-limiting step in synthesis of dopamine, norepi, and epi?

Answer 12

Tyrosine hydroxylase (conversion of L-tyrosine –> L-dopa)

Question 13

Phenylephrine (Neo-synephrine/Sudafed)

Answer 13

a1 agonist

Vasoconstrictor

• during surgery to raise BP
• nasal decongestants
• priapism

Question 14

Clonidine (Catapres)

Answer 14

a2 agonist - inhibits further release of NE

Emergency anti-hypertensive, used frequently in ERs

Question 15

Alpha-methyldopa (Aldomet)

Answer 15

a2 agonist - inhibits further release of NE

Choice anti-hypertensive in pregnant women

Question 16

What are 2 side effects of Sudafed/Phenylephrine?

Answer 16

high BP, urinary retention

Question 17

Dobutamine (Dobutrex)

Answer 17

B1 agonist - increases CO

Used in cardiogenic and septic shock to increase CO; also used for cardiac stress test and acute CHF

Question 18

Albuterol (***terol)

Answer 18

B2 agonist

Asthma, COPD (relieve bronchospasm) - bronchodilator

Question 19

Salmeterol, Formoterol. Metaproterenol

Answer 19

LABAs - Long-acting B2 agonists

Bronchodilator
Asthma, COPD

Question 20

Ritodrine (Yutopar)

Answer 20

B2 agonist

Relaxes smooth muscle of uterus by reducing uterine contractions - prevents premature deliveries

Question 21

What is the drug of choice to treat anaphylactic shock? Name target receptors and how they help.

Answer 21

Epinephrine (epi pen!)

a1 - constricts blood vessels
B1 - CO increases
B2 - bronchodilates & inhibits degranulation of mast cells

Question 22

What are 5 adverse effects of adrenergic agonists?

Answer 22

Increased blood pressure, tachycardia & cardiac arrhythmias, nervousness/anxiety, hyperglycemia, exaggerated effects with cocaine

Question 23

What is rebound HTN?

Answer 23

High BP when a drug is stopped abruptly

Question 24

What is a potential adverse side effect of a2 agonists?

Answer 24

Rebound HTN

Question 25

What do Beta 3 agonists do? Where are the receptors located?

Answer 25

Promote breakdown of triglycerides - lose weight! Mostly in adipose tissue and skeletal muscle

Question 26

Ephedrine

Answer 26

Structural analogs that increase NE levels Nasal decongestant, used during surgeries to raise BP

Question 27

What part of the brain do ADD drugs target?

Answer 27

RAS - reticular activating system in midbrain

Question 28

Tyramine

Answer 28

Precursor to NE - rich in wines and cheeses Indirect acting agonist - structural analog that increases NE levels and mimics its actions Contraindicated with MAO inhibitors

Question 29

What are the neurotransmitter issues in the following conditions? 1. Alzheimer's 2. Depression 3. Parkinson's 4. Schizophrenia 5. ADD

Answer 29

1. Alzheimer's - too little ACh 2. Depression - too little serotonin, NE 3. Parkinson's - too little dopamine 4. Schizophrenia - too much dopamine 5. ADD - too little NE and DA in RAS

Question 30

What is the treatment for the following conditions: 1. Alzheimer's 2. Depression 3. Parkinson's 4. Schizophrenia 5. ADD

Answer 30

1. Increase ACh with esterase inhibitors 2. SSRIs, TCAs 3. L-dopa 4. Dopamine (D2) blockers 5. Ritalin, Adderall

Question 31

Isoproterenol (Isuprel)

Answer 31

Beta-1 = Beta-2 = Beta-3 agonist Causes vasodilation (why there is marked decreased diastolic pressure), but also increases cardiac force and rate (increase in systolic pressure) Reference drug

Question 32

Dopamine (Intropin)

Answer 32

D1, D2 > Beta-1 > alpha-1 agonist (D1, Gs, high cAMP, EPSP) and (D2, Gi, low cAMP, IPSP) Low dose (0.5-2.0 ug/min) - D1 - vasodilation in renal, mesenteric, coronary, and cerebral vasculature, promotes Na+ and H2O excretion Med dose (5-10 ug/min) - D1 & B1 - increase CO High dose (10-50 ug/min) - a1 - vasoconstriction TREATS: Cardiogenic & hypovolemic shock, CHF

Question 33

Epinephrine (Adrenaline)

Answer 33

alpha-1, alpha-2, beta-1, beta-2, beta-3 agonist Higher concentration - a1 - vasoconstriction Lower concentration- B2 - vasodilation Increases heart rate and contractility (so systolic pressure increases), but dilates blood vessels (so diastolic decreases)

Question 34

Norepinephrine (Levofed)

Answer 34

alpha-1, alpha-2, beta-1 agonist Reflex bradycardia - constricts all blood vessels, increasing peripheral resistance, so reflex is to reduce heart rate to try and reduce this pressure

Question 35

Methylphenidate (Ritalin)

Answer 35

Indirect acting agonist - structural analog that increases NE & dopamine levels and mimic their actions #1 drug ADHD

Question 36

D-Amphetamine (Adderall)

Answer 36

Indirect acting agonist - structural analog that increases NE & dopamine levels and mimic their actions #2 drug aDHD