Adrenergic Agonists and Antagonists

Question 1

Epinephrine

Answer 1

direct acting agonist

• all receptors but A favored
• anaphylactic shock, acute asthma, cardiac arrest, anesthetics

Question 2

Norepinephrine

Answer 2

direct acting agonist

• all receptors but A favored
• shock – b/c it increases vascular resistance and therefore increases BP.

Question 3

Albuterol and Terbutaline

Answer 3

direct acting agonist

• B2
• chronic treatment of asthma, bronchitis, etc.

Question 4

Clonidine

Answer 4

direct acting agonist

• A2
• lower BP, minimizes symptoms of withdrawal from opiates or benzodiazepams.

Question 5

Dobutamine

Answer 5

direct acting agonist

• B1
• increase CO in congestive heart failure as well as for inotropic support after cardiac surgery.

Question 6

Dopamine

Answer 6

direct acting agonist

• A1, B1, D1 and D2
• Treatment of shock (b/c alpha and beta blocking drugs have no effects on the dopaminergic receptors). Increases BP to increase CO (B1) and increases total peripheral resistance (A1)

Question 7

Fenoldopam

Answer 7

direct acting agonist

• D1, A2
• Severe HTN

Question 8

Isoproterenol

Answer 8

direct acting agonist

• B1 and B2
• stimulate heart in emergency situations

Question 9

Metaproterenol

Answer 9

direct acting agonist

• B2
• asthma

Question 10

Phenylephrine

Answer 10

direct acting agonist

• favors A1 over A2
• raises both systolic and diastolic BPs but induces bradycardia reflex when given parenterally. Can act as a nasal decongestant producing prolonged vasoconstriction.

Question 11

Salmeterol and Formoterol

Answer 11

direct acting agonist

• B2
• nocturnal asthma (w/corticosteroid)

Question 12

Oxymetazoline

Answer 12

direct acting agonist

• A1 and A2
• nasal spray decongestant and ophthalmic solutions for decrease in red eyes

Question 13

Amphetamine

Answer 13

indirect acting agonist

• A and B
• ADHD – hyperactivity, narcolepsy and appetite control

Question 14

Cocaine

Answer 14

indirect acting agonist

-block Na+ and K+ activated ATPase (required for cellular uptake of norepinephrine). Enhances sympathetic activity.

Question 15

Tyramine

Answer 15

indirect acting agonist

-not clinically useful

Question 16

Ephedrine

Answer 16

direct/indirect acting agonist

• A, B and CNS
• chronic asthma – to prevent attacks. Improves motor function in MG in conjunction w/ anticholinesterases inhibitors. Stimulates CNS alertness, decreases fatigue and prevents sleep. Improves athletic performance. Asthma as a nasal decongestant due to its local vasoconstrictor action. Raise BP

Question 17

Pseudoephedrine

Answer 17

direct/indirect acting agonist

• A, B and CNS
• nasal and sinus congestion or congestion of the eustachian tube.

Question 18

Phenoxybenzamine

Answer 18

antagonist - alpha blocker
A1 post synaptic and A2 presynaptic-irreversible and noncompetitive
-phenochromocytoma – a catecholamine-secreting tumor. Phenoxybenzamine initiates a hypertensive crisis before surgery which allows manipulation of the tissue. Can also be used for chronic management of these tumors.
-Raynaud’s disease.

Question 19

Phentolamine

Answer 19

antagonist - alpha blocker
A1 and A2-competitive
-short term management of pheochromocytoma. Rarely used now for impotence

Question 20

Prazosin,Terazosin and Doxazosin

Answer 20

antagonist - alpha blocker
A1-selective competitive
-HTN

Question 21

Alfuzosin and Tamulosin

Answer 21

antagonist - alpha blocker
A1-selective competitive
-bengin prostatic hyperplasia

Question 22

Yohimbine

Answer 22

antagonist- alpha blocker
A2-selective competitive
-sexual stimulant and Raynaud’s disease

Question 23

Acebutolol, Atenolol, Metoprolol and Esmolol

Answer 23

antagonist - beta blocker
B1-selective
-HTN (good w/diabetic HTN pts who are receiving insulin)

Question 24

Labetalol and Carvedilol

Answer 24

antagonist-beta blocker
A1, B1 and B2 - reversible
-HTN (elderly) and congestive heart failure. Labetalol treatment of pregnancy HTN and can be given IV in HTN emergencies.

Question 25

Nebivolol

Answer 25

antagonist-beta blocker B1, increase NO? -HTN

Question 26

Pindolol and Acebutolol

Answer 26

antagonist - beta blocker B1, B2 and ISA -HTN w/moderate bradycardia. Used in diabetic s w/HTN (b/c of carbohydrate metabolism is less affected w/these drugs)

Question 27

Propanolol

Answer 27

antagonist-beta blocker B1 and B2 - nonselective -HTN, migraine, hyperthyroidism, angina pectoris, supraventricular cardiac arrhythmias and myocardial infarction

Question 28

Timolol

Answer 28

antagonist - beta blocker B1 and B2 - nonselective -Glaucoma (open angle), HTN (occasionally)

Question 29

Nadolol

Answer 29

antagonist - beta blocker B1 and B2 - nonselective -HTN

Question 30

Reserpine

Answer 30

antagonist - affecting NT uptake/reuptake -blocks the Mg2+/adenosine triphosphate-dependent transport of biogenic amines, norepinephrine, dopamine and serotonin from the cytoplasm into the storage vesicles in the adrenergic nerves of all body tissues. Sympathetic function is impaired b/c of decreased release of norepinephrine.

Question 31

Guanethidine

Answer 31

antagonist - affecting NT uptake/reuptake -blocks the release of stored norepinephrine and displaces norepinephrine from storage vesicles transient increase in BP.

Question 32

Cocaine

Answer 32

antagonist - affecting NT uptake/reuptake | -blocks the reuptake of the monoamines into the pre-synaptic terminals.