Epinephrine

Question 1

Drug Classification

Answer 1

Sympathomimetic / Sympathetic agonist / Catecholamine

Question 2

Mechanism of Action

Answer 2

α1agonist → second messenger release of calcium in VSMC → peripheral vasoconstriction → increased SVR → increased BP
β1agonist → increased intracellular Ca2+in cardiac cells → positive inotropy, chronotropy, dromotropy
β2agonist → bronchial smooth muscle relaxation → bronchodilation
Blocks release of calcium in and subsequent destruction of MAST cells

Question 3

Pharmacokinetics

Answer 3

Onset of Action < 2 minutes IV, 3-10 minutes IM
Peak Effects < 5 minutes IV, 20 minutes IM
Duration of Effect = 5-10 minutes IV, 20-30 minutes IM
Half-Life = 5 minutes IV

Question 4

Indications

Answer 4

Cardiac arrest
Anaphylaxis/Severe reactive airway disease/asthma
Symptomatic bradycardia/hypotension/refractory anaphylaxis

Question 5

Contraindications

Answer 5

Tachydysrhythmias

Question 6

Side effects/Adverse reactions

Answer 6

Dysrhythmias, dizziness, anxiety, tremulousness, headache, nausea & vomiting

Question 7

Dose

Answer 7

Cardiac arrest (ADULT): 1mg rapid IV, IO [1:10,000] q 3-5 min
Cardiac arrest (PEDI): 0.01mg/kg rapid IV, IO [1:10,000] q 3-5 min 

Anaphylaxis/Asthma (ADULT): 0.3mg [1:1000] IM q 5 min x 3 doses
Anaphylaxis/Asthma (PEDI): 0.01mg/kg [1:1000] IM (max 0.3mg) q 5 min until S/S resolve

Bradycardia/Hypotension/Refractory Anaphylaxis (ADULT): 2-10 µg/min IV, IO infusion

Refractory Anaphylaxis (PEDI): 0.1-2µg /kg/min (max 10/µg /min) IV, IO infusion
Bradycardia (PEDI): 0.01mg/kg IV, IO [1:10,000] q 3-5 min

Question 8

Precautions

Answer 8

Should be protected from light, caution with CAD

Leads to increased myocardial oxygen demand

Question 9

Drug Interactions

Answer 9

pH dependent, deactivated by alkaline solutions; effect intensified with patients taking antidepressants, reacts with CaCl2and NaHCO3to form precipitate in IV tubing