Vasopressors Flashcards Preview

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Flashcards in Vasopressors Deck (24):
1

phenylephrine

Noncatecholamine with mainly direct alpha1 agonist activity --> mainly causes peripheral vasoconstriction; tachyphylaxis

2

Ephedrine

Noncatecholamine with direct an indirect effects that increase BP, HR, contractility, and CO, also bronchodilates

3

What are alpha 1 receptors?

Postsynaptic receptors that when activated increase intracellular calcium and leads to muscle contraction

4

Alpha 1 effects

Mydriasis, bronchoconstriction, vasoconstriction, uterine contraction, contraction of sphincters, inhibits insulin secretion and lipolysis

5

What are alpha 2 receptors?

Presynaptic receptors that when activated inhibit adenylate cyclase that decreases entry of calcium and exocytosis of norepinephrine from vesicles

6

Alpha 2 effects

Vasoconstriction and negative norepinephrine feedback loop; CNS receptors cause sedation and decreased sympathetic outflow

7

What are beta 1 receptors?

Postsynaptic receptors located on the heart

8

Beta 1 effects

Positive chronotrope (HR), dromotrope (conduction), inotrope (contractility)

9

What are beta 2 receptors?

Postsynaptic receptors found in smooth muscle and glands

10

Beta 2 effects

Relaxes smooth muscle - bronchodilation, vasodilation, relaxation of uterus (tocolysis), bladder, and gut, stimulates glycogenolysis, gluconeogenesis, and insulin release; activates sodium/potassium pump (K into cell)

11

What is methyldopa? Effects?

Alpha 2 agonist that is converted to alpha methylnorepinephrine and alpha methylepinephrine, and caused decreased norepinephrine release and sympathetic tone

12

What is clonidine? Effects?

Alpha 2 agonist that is a sedative, anxiolytic, analgesic, antihypertensive, and negative chronotrope, bradycardia, respiratory depression

13

What is dexmedetomidine? Effects?

Alpha 2 agonist that causes sedation, analgesia, and sympatholytic without significant respiratory depression

14

What happens with rapid dexmedetomidine administration?

HTN but ongoing therapy can cause hypotension and bradycardia

15

Epinephrine beta 1

Direct beta 1 stimulation causes increase CO and myocardial demand by increasing contractility and HR

16

Epinephrine alpha 1

Decreases splanchnic and renal blood flow, increase coronary and cerebral perfusion pressure

17

Epinephrine beta 2

Relaxes bronchial smooth muscle, vasodilation in skeletal muscle may decrease diastolic BP

18

Epinephrine 1:1,000

1 mg per ml

19

Epinephrine 1:10,000

100 mcg/ml (0.1 mg/ml)

20

Epinephrine 1:100,000

10 mcg/ml (0.01 mg/ml)

21

Epinephrine 1:200,000

5 mcg/ml (0.005 mg/ml)

22

What is norepinephrine?

Direct alpha 1 and beta 1 stimulation

23

What is dobutamine? Effects?

Relatively selective beta 1 agonist increases CO and contractility, less increase in HR , while beta 2 prevents increased BP --> LV filling pressure decreases and coronary blood flow increases

24

Which patient is ideal for dobutamine?

Patients with CAD and CHF especially if peripheral vascular resistance and HR are high