Adrenergic Agents

Question 1

Direct Sympathomemetics

Answer 1

Epinephrine, Norepinephrine, Dopamine, Dobutamine

Question 2

Epinephrine

Answer 2

• Alpha 1 agonist at high doses, and B agonist at low dose.
• Vasoconstriction (a1) and increases HR and contractility (B1), and bronchodilation (B2).
• Cardiac arrest and severe hypotension. Bronchospasm and anaphylaxis.

Question 3

Norepinephrine

Answer 3

• Potent a1, a2, and B1 agonist.
• Vasoconstriction, and increase heart contractility.
• For severe hypotension and shock.

Question 4

Dopamine

Answer 4

• a1 at high doses, B and D1 at low doses.
• Vasoconstriction, increase HR and contractility, and promotes renal perfusion.
• Treatment of severe hypotension and shock.

Question 5

Dobutamine

Answer 5

• B1 agonist, weak a1 and B2 (more vasodilation than vasoconstriction)
• Increase HR and contractility.

Question 6

Indirect Sympathometics

Answer 6

Ephedrine and Cocaine

Question 7

Cocaine

Answer 7

• Blocks the Na+/ K+ ATPase that is respinsible for the reuptake of NE, 5’HT, and DA.
• Block VG Na+ channels
• SE: HTN, drug of abuse, cardiac ischemia, and cardiac arrhythmias.

Question 8

Ephedrine

Answer 8

• Stimulating release of NE and Epi; increase systolic and diastolic BP, bronchodialtion, and stimulate CNS.
• Pseudoephedrine- nasal decongestant.
• Amphetamine/ Methylphenidate used to tx narcolepsy and ADHD (stimulates the release of NE, 5’HT, and DA).

Question 9

Adrenergic Agonists

Answer 9

• Phenylephrine, Midodrine, Clonidine, Isoproterenol, Albuterol, Terbulatine.

Question 10

Phenylephrine

Answer 10

• a1 agonist; systemic vasoconstriction

- Severe hypotension and shock, treat nasal congestant, produce mydriasis for retinal examination.

Question 11

Midodrine

Answer 11

• a1 agonist; systemic vasoconstriction (no effect on heart and brain)
• Used to treat orthostatic hypotension.
• SE: supine hypertension.

Question 12

Clonidine

Answer 12

• a2 agonist; decreased central adrenergic activity w/ resulting decrease in vasoconstriction and decrease in CO and HR.
• Use: HTN
• SE: rebound HTN and sedation.

Question 13

Isoproterenol

Answer 13

• B1 and B2 agonist
• Increase HR and contractility, produce peripheral vasodilation, bronchodilation.
• Use: torsades de pointes, tx of cardiac arrest or complete heart block.

Question 14

Terbutaline/ Ritodrine

Answer 14

• B2 agonist

- Delay preterm labor (reduce contractions)

Question 15

Methyldopa

Answer 15

• a2 agonist
• Decreased central adrenergic activity and resulting decrease in vasoconstriction.
• HTN
• SE: orthostatic hypotension

Question 16

Adrenergic Antagonists

Answer 16

-Phenoxybenzamine, Phentolamine, Prazosin, Propranolol, and Carvedilol, Metoprolol.

Question 17

Phenoxybenzamine

Answer 17

• Irreversible a receptor antagonist.
• Pheochromocytoma.
• Phentolamine: short acting reversible a-receptor antagonist. Used to dx pheochromocytomas.

Question 18

Prazosin

Answer 18

• a1 antagonist; decrease in BP; decrease prostatic and bladder neck contraction.
• HTN and BPH
• SE: “First-dose” syncope.

Question 19

Propranolol

Answer 19

• B1 and B2 receptor antagonist
• Use: HTN, CAD, migraines (cerebral vasodilation).
• SE: bronchoconstriction and fasting hypoglycemia (decreased glycogenolysis, which may lead to hypoglycemia).

Question 20

Carvedilol and Labetalol

Answer 20

• a1, B1, B2 blocker
• Reduce HR and contractility, bronchoconstriction
• Use: Chronic congestive heart failure in addition to ACE inhibitors and diuretics. HTN.

Question 21

Metoprolol, esmolol

Answer 21

• Selective B1 antagonist, HR and contractility decreased.

- Esmolol is shorter acting.

Question 22

Albuterol

Answer 22

• B2 agonist

- Asthma and hyperkalemia (shifts potassium into cell).