Adrenergic Agonists & Antagonists

Question 1

Name the three direct-acting adrenergic agonists

Answer 1

Endogenous catecholamines
B-adrenergic agonists
A-adrenergic agonists

Question 2

What are the three endogenous catecholamines?

Answer 2

Epinephrine
Norepinephrine
Dopamine

Question 3

At low concentrations of epinephrine, which receptors are activated?

Answer 3

Beta 1 & 2

Question 4

At high concentrations of epinephrine, which receptors are activated?

Answer 4

More alpha 1 & some beta 1

Question 5

Which concentration of epinephrine can cause a baroreceptor reflex to occur?

Answer 5

High concentration

*Low does not increase MAP with B2 & B1 activation

Question 6

What are the uses for epinephrine?

Answer 6

Cardiac arrest
Anaphylactic shock
Acute asthmatic attack

Question 7

Which receptors does norepinephrine act on?

Answer 7

A1, A2, B1

*NOT B2

Question 8

Can norepinephrine cause a baroreceptor reflex kick in?

Answer 8

Yes- no B2 action with norepinephrine

Question 9

What are the uses for norepinephrine?

Answer 9

Treat shock

Question 10

What are the control systems of the baroreceptor reflex?

Answer 10

Changes in vasculature lead to reading by baroreceptors on carotid sinus, this leads to change in heart contraction by sympathetic centers and change in heart rate by vagal centers

Question 11

Which non-selective adrenergic agonist acts on Beta1 & Beta2 receptors and is used to stimulate the heart in patients with brachycardia or heart block?

Answer 11

Isoproterenol

Question 12

Which selective adrenergic agonist acts on B1 and produces less increase in HR and less decrease in PVR than isopreternol?

Answer 12

Dobutamine

*also increases O2 consumption for stress test

Question 13

Which selective adrenergic agonist acts on B2 receptors and is used in asthma attacks?

Answer 13

Albuterol

Question 14

Which selective adrenergic agonist acts on A1 receptors and is used as a nasal decongestant or to produce mydriasis?

Answer 14

Phenylephrine

Question 15

Which selective & partial adrenergic agonist acts on A2 receptors and inhibits the release of NE, reducing sympathetic outflow?

Answer 15

Clonidine

Question 16

What are the two classes of indirect-acting adrenergic agonists?

Answer 16

Releasing agents & uptake inhibitors

Question 17

Which releasing agent causes NE release, acts on A1 and B1 receptors and is used for ADHD and narcolepsy?

Answer 17

Amphetamine

Question 18

Which releasing agent also causes NE release and is oxidized by MAO?

Answer 18

Tyramine

*if patient is taking MAO inhibitor (antidepressant), tyramine can cause vasopressor episodes

Question 19

Which uptake inhibitor blocks monoamine reuptake resulting in potentiation and prolonging of central and peripheral actions?

Answer 19

Cocaine

Question 20

What are the two mixed-acting adrenergic agonists that act by causing release of NE?

Answer 20

Ephedrine and pseudoephedrine

Question 21

Which mixed-acting agonist is a poor substrate for COMT & MAO, having long duration, penetrates CNS, and is used as a pressor agent for spinal anesthesia?

Answer 21

Ephedrine

Question 22

Which mixed-acting agonist is one of four ephedrine enantiomers and is commonly used in decongestant mixtures (sudafed)?

Answer 22

Pseudoephedrine

Question 23

Name the two types of alpha & beta antagonists

Answer 23

Non-selective alpha or beta antagonists

A1 or B1 selective antagonists

Question 24

Name the two types of non-selective alpha antagonists

Answer 24

Phenoxybenzamine

Phentolamine

Question 25

Which non-selective alpha antagonist acts irreversibly on A1 & A2 receptors, has been found unsuccessful for hypertension cases, and is used prior to tumor removals for pheochromocytoma?

Answer 25

Phenoxybenzamine

Question 26

Which non-selective alpha antagonist acts reversibly on A1 & A2 receptors, can be used to control hypertension in pheochromocytoma pre-ops & surgical removals, and can be used as an antidote for hypertension due to stimulate drug overdoses?

Answer 26

Phentolamine

Question 27

Which selective alpha antagonist is specific for A1 receptors, is used for hypertension (not a DOC), and for symptom relief of benign prostatic hyperplasia?

Answer 27

Prazosin

Question 28

Which non-selective beta antagonist acts on B1 & B2 receptors and cause respiratory crisis in COPD or asthma patients?

Answer 28

Propranolol

Question 29

Which beta selective antagonist acts on B1 receptors and is used in diabetic hypertension patients?

Answer 29

Atenolol

Question 30

Which partial beta antagonist competes with NE and is preferred in patients with diminished cardiac reserve or brachycardia?

Answer 30

Pindolol

Question 31

What are adverse effects of beta blockers?

Answer 31

Bronchoconstriction (avoid with asthmatic patients) Hypoglycemia (avoid in patients with insulin-dependent diabetes due to B2 inhibition of gluconeogenesis —> B1 blocker preferred) CNS - sedation, dizziness, fatigue etc.