VASOPRESSORS and Inotropic Agents

Question 1

Isoproterenol, predominant receptors

Answer 1

beta1- and beta2-adrenergic receptor

Question 2

Isoproterenol, predominant action at receptors

Answer 2

beta1- and beta2-adrenergic receptor agonist

Question 3

Inotrope/chronotrope/vasodilator

Answer 3

Isoproterenol (Chemical pacemaker)

Question 4

Act as a chemical pacemaker?

Answer 4

Isoproterenol.

Question 5

Isoproterenol Dosing (mcg/min AND mcg/kg/min)

Answer 5

5 to 20 mcg/minute OR 0.05 to 0.2 mcg/kg/minute

Question 6

2 major things to know about Isoproterenol

Answer 6

• Exacerbation of hypotension is likely due to dose-dependent vasodilation (via beta2 stimulation)
• May cause arrhythmias

Question 7

Milrinone class

Answer 7

Inotrope/vasodilator (phosphodiesterase inhibitor)

Question 8

Milrinone Mechanism of action

Answer 8

(decreases rate of cyclic adenosine monophosphate [cAMP] degradation)

Question 9

Milrinone major thing to know

Answer 9

Can get hypotension likely due to vasodilation (via phosphodiesterase inhibition); concurrent administration of a potent vasoconstrictor such as norepinephrine or vasopressin may be necessary

Question 10

Milrinone DOSING (Bolus?)

Answer 10

0.375 to 0.75 mcg/kg/minute (a loading dose of 50 mcg/kg over ≥10 minutes may be administered, but is often omitted)

Question 11

Dobutamine Predominant action

Answer 11

Inotrope/vasodilator/dose-dependent chronotropy (beta1- and beta2-adrenergic receptor agonist

Question 12

Dobutamine acts on what receptors?

Answer 12

Beta 1 and Beta 2

Question 13

Dobutamine dosing (mcg/kg/min) (mcg/min)

Answer 13

1 to 20 mcg/kg/minute

Question 14

Dobutamine : 1 thing to know

Answer 14

Exacerbation of hypotension is possible due to dose-dependent vasodilation (via beta2 stimulation); concurrent administration of a potent vasoconstrictor such as norepinephrine or vasopressin may be necessary

Question 15

Dopamine predominant action

Answer 15

Inotrope/vasopressor/dose-dependent chronotropy

Question 16

Dopamine acts on what receptors ?

Answer 16

Dopaminergic, beta1-, beta2-, and alpha1-adrenergic receptor agonist

Question 17

Dopamine dose

Answer 17

2 to 20 mcg/kg/minute

Question 18

Dopamine effects effects across dose range:

Answer 18

Low doses have primarily dopaminergic effects at <3 mcg/kg/minute
Intermediate doses have primarily beta1- and beta2-adrenergic effects at 3 to 10 mcg/kg/minute
High doses have primarily alpha1-adrenergic effects >10 mcg/kg/minute

Question 19

Dopamine low dose may exacerbate what?

Answer 19

Low doses may exacerbate hypotension via beta2 stimulation

High doses may cause vasoconstriction, adverse metabolic effects, and arrhythmias

Question 20

Dopamine high dose may exacerbate ?

Answer 20

vasoconstriction, adverse metabolic effects, and arrhythmias

Question 21

Vasopressin act on what receptors?

Answer 21

Vasopressin1 and Vasopressin2 receptor agonist

Question 22

Vasopressin bolus dosing

Answer 22

1 to 4 units

Question 23

Vasopressin infusion dosing

Answer 23

0.01 to 0.04 units/minute

Question 24

When is vasopressin dose > 0.04 units/minute indicated?

Answer 24

Doses >0.04 units/minute up to 0.1 units/minute are reserved for salvage therapy (ie, failure to achieve adequate BP goals with other vasopressor agents)¶

Question 25

Effective for treatment of hypotension refractory to administration of catecholamines or sympathomimetics such as ephedrine, phenylephrine, or norepinephrine

Answer 25

Vasopressin

Question 26

No direct effect on HR

Answer 26

Vasopressin

Question 27

PVR

Answer 27

Little effect on PVR; can cause splanchnic vasoconstriction

Question 28

Vasopressin and skin

Answer 28

Peripheral extravasation may cause skin necrosis

Question 29

Individual responses to dose-related effects are variable with

Answer 29

Vasopressin

Question 30

Epinephrine vasopressor receptors

Answer 30

Inotrope/chronotrope/vasopressor (alpha1-adrenergic receptor agonist; beta1- and beta2-adrenergic receptor agonist)

Question 31

Epinephrine initial dose and dosing if initial dose inadequate?

Answer 31

4 to 10 mcg initially; up to 100 mcg boluses may be used when initial response is inadequate

Question 32

Epinephrine infusion dose

Answer 32

1 to 100 mcg/minute OR 0.01 to 1 mcg/kg/minute

Question 33

Epinephrine changing effects across dose range:

Answer 33

• Low doses have primarily beta2-adrenergic effects at 1 to 2 mcg/minute or 0.01 to 0.02 mcg/kg/minute
• Intermediate doses have primarily beta1- and beta2-adrenergic effects at 2 to 10 mcg/minute or 0.02 to 0.1 mcg/kg/minute
• High doses have primarily alpha1-adrenergic effects at 10 to 100 mcg/minute or 0.1 to 1 mcg/kg/minute

Question 34

First-line treatment for cardiac arrest and for anaphylaxis

Answer 34

Epinephrine

Question 35

May be administered IV, IM, or via an endotracheal tube in emergencies

Answer 35

Epinephrine

Question 36

Low doses of epinephrine cause

Answer 36

bronchodilatory effects and may cause arterial vasodilation and decreased BP

Question 37

Intermediate doses of epinephrine cause

Answer 37

Intermediate doses cause increases in HR and BP

Question 38

High doses of epinephrine cause

Answer 38

vasoconstriction, with possible severe hypertension and adverse metabolic effects

Question 39

Norepinephrine boluses

Answer 39

Inotrope/vasopressor (alpha1- and beta1-adrenergic receptor agonist) 4 to 8 mcg (may begin infusion if repeated bolus doses are necessary)

Question 40

Often selected as a first-line agent during non-cardiac surgery, particularly for treatment of most types of shock

Answer 40

Norepinephrine

Question 41

Norepinephrine vs phenylephrine potency

Answer 41

Norepinephrine 8 mcg is approximately equivalent in potency to phenylephrine 100 mcg

Question 42

Norepinephrine Dosing

Answer 42

1 to 20 mcg/minute OR 0.01 to 0.3 mcg/kg/minute

Question 43

Peripheral extravasation of a high concentration may/cause tissue damage

Answer 43

Norepinephrine

Question 44

Ephedrine 5 to 10 mg boluses N/A

Answer 44

Inotrope/chronotrope/vasopressor (alpha1​-adrenergic receptor agonist; beta1- and beta2-adrenergic receptor agonist)

Question 45

Ephedrine should be administered with extreme caution

Answer 45

Administered with extreme caution (eg, in small incremental doses of 2.5 mg) to patients using monoamine oxidase (MAO) inhibitors or methamphetamines since exaggerated hypertensive responses or life-threatening dysrhythmias may occur

Question 46

Ephedrine multiple doses

Answer 46

Tachyphylaxis may occur with multiple repeated doses due to indirect postsynaptic release of norepinephrine

Question 47

Cardiovascular effects of ephedrine and other drugs.

Answer 47

Cardiovascular effects attenuated by drugs that block ephedrine uptake into adrenergic nerves (eg, cocaine) or those that deplete norepinephrine reserves (eg, reserpine)