Adrenergics

Question 1

What class or type of drug is Epinephrine?

Answer 1

Alpha-beta agonist

Question 2

What is the MOA for Epinephrine? Differences at low, medium, and high dosage?

Answer 2

• At low doses activates B1/B2
• At Medium doses activates B1/B2/a1 (increase in systolic P, decrease in diastolic P)
• At high doses activates a1 (both systolic and diastolic BP increase)

Question 3

What action does epinephrine have on the heart, vasculature, respiration, GI, CNS, eyes, skeletal muscle and metabolism?

Answer 3

• B1 heart: increases HR, increases SV, increases CO, increases PP
• Vessels (a1): vasoconstriction of skin, GI, renal vessels
• Vessels (B2): vasodialation id skeletal muscle liver, decrease TPR, decrease BP
• Respiratory: bronchodialation (B2) and increased mucociliary secretions
• GI: smooth muscle relaxant, decrease peristalsis, contraction of sphincters (a1)
• CNS: no CNS entry
• Eye: Constriction of radial muscle (mydriasis), decrease intraocular P (a2)
  -Skeletal m: tremor (B2, Ca2+ sequestration)
  Metabolic: inhibit insulin secretion, enhance glycogenolysis and gluconeogenesis, increase renin secretion, inhibit mast cell degranulation, stimulate platelet aggregation

Question 4

What are the clinical uses of epinephrine?

Answer 4

• Anaphylaxis
• Prevent surgical bleeding
• Slow absorption of local anesthetics
• Asthma
• Open angle glaucoma
• Resuscitation in cardiac arrest

Question 5

What are the adverse effects of epinephrine?

Answer 5

CNS: Fear, anxiety, headache, tremor, weakness

CVS: HTN, reflex bradycardia

Contraindications:
HTN, hyperthyroidism, angina, heart disease, shock, diabetes

Question 6

What class or type of drug is Norepinephrine?

Answer 6

Alpha-beta agonist (not B2 agonist)

Question 7

Wha it is the MOA for norepinephrine?

Answer 7

Activation of B1, a1, a2 receptors

Question 8

What action does norepinephrine have on the CVS and vasculature?

Answer 8

• CVS: same as Epi (increases systolic and diastolic BP), reflex bradycardia
• Vessels: Vasoconstriction

Question 9

What are the clinical uses of norepinephrine?

Answer 9

-Hypotension and vasodilatory shock

• Slow absorption of local anesthetics

Question 10

What are the adverse effects of norepinephrine?

Answer 10

Same as epinephrine but symptoms are less frequent

Question 11

What class or type of drug is Phenylephrine?

Answer 11

Alpha (a1) agonist

Question 12

What action does Phenylephrine have on CVS?

Answer 12

• CVS: increase BP by activation of vagal reflexes
• Increase TPR, BP (a1)

Question 13

What are the clincial uses of Phenylephrine?

Answer 13

Vasodilatory shock, nasal congestion and bleeding, postural HTN

Question 14

What are the adverse effects of Phenylephrine?

Answer 14

Hypertension, anginal pain, rebound congestion, photophobia (mydriasis)
Contraindication: hyperthyroidism, urinary retention

Question 15

What class or type of drug is Clonidine?

Answer 15

Alpha (a2) and imidzoline agonists

Question 16

What is the MOA of Clonidine?

Answer 16

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