Norepinephrine

Question 1

Alternate Names

Answer 1

Noradrenaline, Levophed, leave-em-dead

Question 2

Drug Class (Pharmacologic and Therapeutic)

Answer 2

1. Pharmacologic Class - direct acting adrenergic agonist

2. Therapeutic Class - vasopressor, vasoconstrictor

Question 3

Pharmacodynamics

Answer 3

Major action: stimulate peripheral alpha 1 adrenoreceptors -> leading to vasoconstriction (resistance arterioles, increases SVR) and venoconstriction (inc. preload) –> Increase CO, SVR, and MAP
Alternate Action: stimulates beta - 1 receptors in the heart, inc. HR and contractility
Overall Action: vasoconstriction and cardiac stimulation
Negatives: dec. blood flow to vulnerable tissues like skin, muscle, kidney.

Question 4

Pharmacokinetics:

Answer 4

F ~ 100%; GIVEN IV ONLY. Metabolized by COMT and MAO mostly in LIVER; Metabolites excreted in URINE; Can cross the placenta but not the BBB

Question 5

Half Life

Answer 5

1-2 minutes (titrated quickly IV)

Question 6

Toxicity

Answer 6

excessive vasoconstriction in mesenteric vessels, peripheral arterioles causing ischemia, infarction, gangrene; reflex bradycardia

Question 7

Interactions

Answer 7

Caution in patients taking MAOIs such as PHENELZINE (use lower dose); risk of excessive hypertension in patients taking propranolol ?

Question 8

Special Considerations

Answer 8

Correct volume depletion with IV fluids BEFORE giving NE infusion; select infusion site carefully - extravasation is a major problem; monitor patient and BP continuously in ICU setting; use cautiously in pediatric and geriatric patients

Question 9

Indications and Dose / Route

Answer 9

For adults with acute hypotension and shock (related to low SVR); Infuse 2-12 mcg/min

Question 10

Monitor

Answer 10

BP, HR, infusion site, evidence of extravasation