Vasopressors

Question 1

Isoproterenol

Answer 1

B1 and B2 adrenergic receptor agonists

• Used for bradycardia —> increases HR
• increases BP
• increases CO through B1 adrenergic stimulation

Question 2

Epinephrine

Answer 2

• alpha 1 agonist - arteries constrict which increase BP and blood flow to the heart
• Stimulates alpha, beta 1 and beta 2 receptors resulting in relaxation of smooth muscle, cardiac stimulation, and dilation of skeletal muscle vasculature
• causes vasoconstriction and also in the heart, increases the rate and force of contraction
• MORE ACTIVITY ON HEART
• Used for bradycardia

Question 3

Norepinephrine

Answer 3

-stimulates alpha 1 to cause peripheral vasoconstriction and increase BP
- B1 receptor agonist activity in increasing heart rate and blood pumping from the heart
- more effect on blood vessel
Used to increase BP

Question 4

Vasopressin

Answer 4

V1 receptor stimulates smooth muscle contraction, increasing BP
V2 receptors primarily act in the kidney to produce water retention (antidiuretic hormone) —> decreases water excretion by the kidneys by increasing water reabsorption in the collecting ducts,
V3 central nervous system

Question 5

Phenylephrine

Answer 5

Alpha 1 agonist
Located on the vascular smooth muscle
- vasoconstriction (increase BP)

Question 6

Clonidine & Methyldopa

Answer 6

Alpha 2 agonists
Located on presynaptic nerve ending
Decreases BP
RELEX: increases HR

Question 7

Dexmedetomidate (Precedex)

Answer 7

Alpha 2 receptor agonist on pre-synaptic membranes
- inhibits release of NE
SE: hypotension and bradycardia

Question 8

Prasozin, tamsulosin, alfuzosin

Answer 8

Alpha 1 blocker

Caution: syncope due to orthostatic HTN after initial dose, dizziness, fatigue; titrate