Adrenergics

Question 1

What receptors does epineprhine target?

Which is it selective for?

Answer 1

α₁ = α_{<span>2</span>}; β₁ = β₂

α effects seen more at higher [c], β effects seen more at lower [c]

Question 2

What are the expected effects of epineprhine?

Answer 2

Heart:

-increase rate and force of cardiac contraction (increase cardiac output β₁)

Vasculature:

-increase systolic BP (A constriction, α₁) w/ some diastolic decrease (V dilation β2), no change in MAP

Lung:

-bronchodilation (β₂)

Muscle:

-increases potassium uptake (β₂)

Liver:

-increases glycogenolysis and gluconeogenesis (β₂)

Question 3

What receptors does norepineprhine target?

Which is it selective for?

Answer 3

General alpha agonist:

α₁ = α₂ > β₁ >> β₂

Question 4

What are the expected effects of norepineprhine?

Answer 4

Heart:

-increased force of contraction (α₁)

Vasculature:

-A and V constriction (α₁) > increased BP and MAP > reflex bradycardia

Question 5

What receptors does phenyleprhrine target?

Which is it selective for?

Answer 5

Selective α₁ agonist:

α₁ > α₂ >>>>> β_1/2

Question 6

What are the expected effects of phenyleprhrine?

Answer 6

Eyes:

-mydriasis (dilation) (α₁)

ENT:

-mucosal vasoconstriction (α₁) -> decongestant

Vasculature:

-SEVERE vasoconstriction (α₁) -> increased BP and MAP -> SEVERE reflex bradycardia

Question 7

What receptors does clonidine target?

Which is it selective for?

Answer 7

Selective α₂ agonist:

α₂ > α₁ >>>>> β

Question 8

What are the expected effects of clonidine?

Answer 8

Brain:

• decreased activity in vasomotor center -> bradycardia and decreased BP
• decreased sympathetic response

Question 9

What receptors does isoproterenol target?

Which is it selective for?

Answer 9

Non-selective β agonist:

β₁ = β₂ >>>> α

Question 10

What are the expected effects of isoproterenol?

Answer 10

Heart:

-increased force and rate of contraction (increased cardiac output β_1​)

Vasculature:

-vasodilation (β₂) -> decreased diastolic BP

Lungs:

-bronchodilation (β₂)

Question 11

What receptors does dobutamine target?

Which is it selective for?

Answer 11

Selective β₁ agonist:

β₁ > β₂, α₁

Has selective α₁ activity

Question 12

What are the expected effects of dobutamine?

Answer 12

Heart

• increased force of contraction (β₁)
• slight increase in rate (β₁ dampened by α₁?)
• increased cardiac output

Question 13

What receptors does albuterol target?

Which is it selective for?

Answer 13

Selective β₂ agonist:

β₂ > β₁ >>>> α

Question 14

What are the expected effects of albuterol?

Answer 14

Lungs:

broncodilation (β₂)

Question 15

What does cocaine do?

Answer 15

Blocks dopamine and NE reuptake from synaptic cleft -> adrenergic effect

Question 16

What does phenelzine do?

Answer 16

Inhibits MAO -> adrenergic effect

Question 17

What does selegine do?

Answer 17

Inhibits MAO -> adrenergic effect

Question 18

What do amphetamines do?

Answer 18

Increase release of dopamine and NE -> adrenergic effect

Question 19

What does methylphenidate do?

Answer 19

Increase release of dopamine and NE -> adrenergic effect

*Ritalin

Question 20

What does ephedrine do?

Answer 20

Direct receptor agonist and increases release of dopamine and NE

Question 21

What does tyramine do?

Answer 21

Increases release of dopamine and NE

Unable to cross BBB and therefore not used as a drug.

Used diagnostically to evaluate peripheral adrenergic function (increases SBP)

Question 22

What adrenergics would be most effective in treating acute hypotensive emergencies?

Answer 22

• norepinephrine (non-selective α agonist, increased force of contraction and vasoconstriction) (reflex bradycardia)
• phenylephrine (selective α₁ agonist significant increase in vasoconstricton) (reflex bradycardia)

Question 23

What adrenergics would be most effective in treating chronic hypotension?

Answer 23

-Ephedrine (increase release of dopamine/NE and direct receptor agonist)

Question 24

What adrenergics would be most effective in treating cardiogenic shock?

Answer 24

-dobutamine (selective β₁ agonist, increased force and rate of contraction)

Question 25

What adrenergics would be most effective in treating hypertension?

Answer 25

Clonidine (α₂ agonist, depression of vasomotor center)

Question 26

What adrenergics would be most effective in treating a complete AV block or cardiac arrest?

Answer 26

• epinephrine (α and β agonist, increased cardiac output and increased conduction velocity at AV node)
• isoproteronol (non-selective β agonist, increased cardiac output)

Question 27

What adrenergics would be most effective in treating depression?

Answer 27

-phenelzine and selegine (MAO inhibitors)

Question 28

What adrenergics would be most effective in treating asthma?

Answer 28

-albuterol (selective β₂ agonist, bronchodilation)

Question 29

What adrenergics would be most effective in treating congestion of mucous membranes?

Answer 29

• phenylephrine (selective α₁ agonist, vasoconstricion of vasculature in mucous membrane)
• ephedrine

Question 30

What adrenergics would be most effective in treating anaphylaxis?

Answer 30

-epinephrine (α and β agonist, increased cardiac output and bronchodilation)

Question 31

What adrenergics would be most effective in facilitating retinal examinations?

Answer 31

-phenylephrine (selective α₁ agonist, mydriasis/pupilary dilation)

Question 32

What adrenergics would be most effective in treating glaucoma?

Answer 32

-selective α₂ agonists (decrease aqueous humor production from ciliary body)