Drugs Affecting Adrenergic Neurotransmission

Question 1

General actions of sympathetic stimulation

Answer 1

increased rate + force of heart contraction, blood pressure, and blood glucose levels
shift of blood flow to skeletal muscles
dilation of bronchioles and pupils

Question 2

Where is norepinephrine made?

Answer 2

within adrenergic neurons near the terminus of the axon near the junction with the effector cell

Question 3

Where is epinephrine made?

Answer 3

the adrenal medulla

Question 4

Which amino acid does epinephrine come from?

Answer 4

tyrosine

Question 5

Alpha 1A receptor

Answer 5

causes contraction of smooth muscle, promotes cardiac growth and structure, vasoconstriction of large resistant arterials in skeletal muscle

Question 6

Alpha 1 B receptor

Answer 6

promotes cardiac growth and structure

Question 7

Alpha 1 C receptor

Answer 7

causes vasoconstriction in aorta and coronary artery

Question 8

Alpha 2A receptor

Answer 8

predominant inhibitory receptor on sympathetic neurons
vasoconstriction of small procapillary vessels in skeletal muscle

Question 9

Alpha 2B receptor

Answer 9

predominant receptor mediating alpha 2 vasoconstriction

Question 10

Alpha 2c receptor

Answer 10

predominant receptor modulating dopamine neurotransmission
predominant receptor inhibiting hormone release from the adrenal medulla

Question 11

Beta 1 receptor

Answer 11

predominant receptor in heart producing positive inotropic and chronotropic effects

Question 12

Beta 2 receptors

Answer 12

predominant receptor in smooth muscle relaxation
skeletal muscle hypertrophy

Question 13

beta 3 receptor

Answer 13

predominant receptor producing metabolic effects

Question 14

How many transmembrane domains do adrenergic receptors have?

Answer 14

7

Question 15

Which G protein are beta receptors coupled to ?

Answer 15

Gs

Question 16

Which G protein is the alpha 2 receptor coupled to?

Answer 16

Gi

Question 17

Which G protein is the alpha 1 receptor coupled to?

Answer 17

Gq

Question 18

Direct acting agonists

Answer 18

norepinephrine
tetrahydrozoline
clonidine
dobutamine
albuterol

Question 19

indirect acting agonists

Answer 19

increase the availability of norepinephrine or epinephrine to stimulate adrenergic receptors

Question 20

Mixed Acting Agonists

Answer 20

indirectly release norepinephrine and also directly activate adrenergic receptors

Question 21

A nitro group will deactivate the catechol which inhibits ?

Answer 21

COMT

Question 22

Catechols are not recognized by ?

Answer 22

MAO

Question 23

COMT inhibitors

Answer 23

treatment for parkinson’s
prolong half life of levodopa

Question 24

MAO inhibitors

Answer 24

second line treatment for depression
may cause hypertensive crisis
increased norepinephrine leads to increased vasoconstriction

Question 25

Phenylethanolamines

Answer 25

direct/mixed/indirect agonists primary/secondary aliphatic amine separated by 2 carbon atoms from a benzene ring a secondary hydroxyl group at the benzylic carbon primarily ionized at physiological pH pKa 9-11

Question 26

What is significant about the N-CH3 on epinephrine?

Answer 26

it maximizes activity

Question 27

For phenylethanolamines what happens as you increase the size of the N group

Answer 27

greatly decrease alpha activity due to differences in the binding pockets

Question 28

What happens when you remove the 4’ OH on a phenylethanolamine

Answer 28

activity at the alpha receptor is reduced and almost eliminated at the beta receptors

Question 29

Why does ephedrine have a greater duration of action than epinephrine?

Answer 29

no catechol, therefore no COMT metabolism alpha-CH3 means steric hindrance ands blockage from MAO

Question 30

Why does pseudoephedrine primarily act as an indirect mechanism?

Answer 30

has the wrong stereochemistry at OH group, overall too many changes for a direct mechanism

Question 31

Ephedrine, pseudoephedrine and phenylephrine are commonly used as ?

Answer 31

Decongestants

Question 32

What are the major therapeutic indications of selective alpha one receptor agonists?

Answer 32

nasal congestion allergic and viral conjunctivitis allergic/vasomotor rhinitis conjunctival hypermedia corneal abrasion vernal keratoconjunctivitis vasoconstriction

Question 33

Which receptor accommodates a more diverse assortment of structural changes?

Answer 33

alpha 1

Question 34

Oxymetazoline, Naphazoline, and Tetrahydrozoline are all available as ?

Answer 34

nasal sprays and ophthalmic solutions