Epinephrine

Question 1

Drug Class (pharmacologic and therapeutic)

Answer 1

1. Pharmacologic class - direct-acting adrenergic agonist
2. Therapeutic class - vasopressor, cardiac stimulant, bronchodilator, adjunct to local anesthetics, treatment for anaphylaxis

Question 2

Pharmacodynamics

Answer 2

Major Action: 1. Stimulate peripheral alpha 1 adrenoreceptors -> vasoconstriction (resistance arterioles inc. SVR) and venoconstriction (inc. preload at capacitance vessels)

2. Stimulate beta 1 receptors -> tachycardia and inc. contractility; ;
3. Beta 2 receptors -> bronchoconstriction
4. Stabilizing mast cells in severe allergic reactions

Question 3

Pharacokinetics

Answer 3

1. Given IV (immediate), IM (variable), SC (5-15min), and via inhalation (1-5 min onset), ophthalmic topical; metabolized by COMT and then renally excreted

Question 4

Toxicity

Answer 4

excessive vasoconstriction, HTN, hemorrhagic stroke, angina, arrhthmias

Question 5

Interactions

Answer 5

risk of excessive hypertension in patients taking propranolol

Question 6

Special considerations

Answer 6

utility with local anesthetics; drug of choice in severe anaphylaxis reactions

Question 7

Indications and dose / route

Answer 7

for anaphylaxis, 0.1-0.5 mg SC or IM; for cardiac arrest, 1-5mg IV push; for infusion 1-4 mcg/min

Question 8

Monitor

Answer 8

BP, HR, rhythm, infusion site, evidence of extravasation