High yield

Question 1

Label the agents for A-C

Answer 1

A) Norepinephrine

B) Epinephrine

C) Isoproterenol

Question 2

What are the effects of epinephrine on skeletal muscle, mediated by which receptors?

Answer 2

• Causes muscle tremor (β2)
• Increases K+ uptake by skeletal muscle (β2) = promotes HYPOkalemia and decreased K+ excretion by kidneys

Question 3

What are the effects of epinephrine on blood glucose, fatty acid levels and renin?

Answer 3

• Elevates blood glucose levels –> enhances liver glycogenolysis and gluconeogenesis (β2)
• Increases free fatty levels in blood
• Increases renin release (β1)

Question 4

What are the major effects of norepinephrine?

Answer 4

• Potent cardiac stimulant BUT reduces HR
• Potent vasoconstrictor
• Increases peripheral vascular resistance and BP; decreases pulse rate

Question 5

What are the adrenergic receptor types found in the vascular beds of the skin vessels/mucous membranes, skeletal muscle, renal, and cerebral?

Answer 5

• Skin vessels and mucous membranes (α1)
• Skeletal muscle (α1 and β2)
• Renal, cerebral (D1 and α1)

Question 6

Clonidine acts on which receptors and produces what effects?

Answer 6

• SELECTIVE α2 agonist
• Central effect on α2 receptors in the lower brainstem area –> decrease sympathetic outflow, reduction in BP, BRADYCARDIA

*Guy holding claw weapons w/ 2 lit candles!

Question 7

Which adrenergic receptors are activated at low doses vs. high doses of Dopamine?

What are the effects?

Answer 7

• At low doses β1 receptors are activated (cardiac activation)
• At high doses α1 receptors are activated (pressor effects)

*Remember D-B-A*

Question 8

Tyramine is found where?

What is the MOA when administered parenterally and how is it metabolized?

Answer 8

• Found in cheese, cured meats, and smoked/pickled fish
• Releases stored NE from presynaptic adrenergic terminals (if administered parenterally)
• Metabolized by MAO in liver (may lead to increased BP in pt’s taking MAO inhibitors)

Question 9

What is the MOA of Metyrosine?

Answer 9

Inhibits tyrosine hydroxylase; prevents conversion of tyrosine –> L-DOPA

Question 10

What is the MOA of Guanethidine?

Answer 10

Prevents storage, depletes NE

Question 11

Which 2 drugs are used in the treatment of chronic urinary retention associated with BPH?

Which receptor do they target?

Answer 11

• Tamsulosin and Silodosin (α1 selective antagonists)
• Greater selectivity for α1_A = most important α receptor subtype mediating prostate smooth muscle contraction

Question 12

How does the (-) isomer of Dobutamine differ from the (+) isomer in its effects on α1 receptors?

Answer 12

• Dobutamine is a selective β1 agonist
• Has some α1 activity: the (-) isomer is an agonist at these receptors and the (+) isomer is an α1 antagonist