Vasopressor

Question 0

Arginine Vasopressor (AVP, ADH)

1) Indication
2) Onset and DOA
3) Metabolism

Answer 0

1) “Potent constrictor of glomerular efferent arteriole (not afferent) = maintaining GFR
Potent constrictor in hemorrhagic or septic shock (esophageal varicies)
Treatment of DI = antidiuresis”

2) “Onset = nasal 1hr DOA = nasal 3-8hrs”

3) “Metabolized by tissue peptidases
Rapid oral inactivation by trypsin
10-20min E1/2t”

Question 1

Arginine Vasopressin (AVP, ADH)

1) Class
2) Action

Answer 1

1) Exogenous antidiuretic peptide and vasopressor

2) “AVP stimulates V1a receptors on vascular smooth muscle, glomerular mesangial cells, and vasa recta.
Increases von Willebrand factor and factor VIII
Stimulates GI smooth muscle = peristalsis

Activates V2 receptors on basolateral cell membrane of renal collecting ducts = ↑water reabsorption
Stimulates fusion of aquaporin2 water channels to apical cell = ↑water reabsorption = antidiuretic”

Question 2

Arginine Vasopressor (AVP, ADH): Adverse Effects

Answer 2

"IV route = Coronary artery vasospasm, angina, MI
Vasoconstriction and HTN in high doses
Increased peristalsis, NV, and abd pain.
Uterine stimulation
Decreased PLTs
Urticarial and anaphylaxis
Tremor
Headache
Fever
diaphoresis"

Question 3

Arginine Vasopressor (AVP, ADH)

1) Contraindications
2) Dosage

Answer 3

1) “Hypersensitivity
NSAIDs and carbamazepine increase AVP”

2) “DI = 100-200mU/hr IV
Esophageal varicies = 20units over 5 mins
Hemorrhagic/septic shock = 0.01-0.1 units/min (0.04)”