Pharm - Catecholamines

Front 1

Name the catecholamines.

Back 1

Epinephrine, norepinephrine, dopamine, fenoldopam, isoproterenol and dobutamine

Front 2

Describe the kinetics of catecholamines.

Back 2

short t1/2 (minutes), degrated rapidly by COMT and MAO, catechol moiety prevents ready absorption and CNS penetration. Must be administered IV.

Front 3

What is the receptor specificity for epinephrine?

Back 3

none

Front 4

What is the mechanism of action of epinephrine?

Back 4

nonspecific agonist to b and a receptors: therefore activation of sympathetic nervous system and all concomitant effects + inotropic and chronotropic effects on heart via b1 R, vasoconstriction of vasculature via a1-R balanced by vasodilation via b2 (PVR may fall and it may increases coronary and cerebral blood flow), b2 activation of bronchilar smooth muscle relaxes airways

Front 5

Clinical uses of epinephrine.

Back 5

glaucoma (increase outflow), anaphylaxis, Hypotension, Heart Failure (HF)-ACLS, reduce local blood flow, severe asthma

Front 6

Toxicity of epinephrine.

Back 6

sympathetic excess (ex: arrythmias, hypertension, cerebral hemorrhage, tachycardia and anxiety)

Front 7

Receptor specificity for norepinephrine.

Back 7

a1=a2; b1>>b2

Front 8

Mechanism of action for norepinephrine

Back 8

similar to epinephrine, however, more specific effects on a1 and b1. é in PVR via a1. Less b2-R activation (less effect of bronchilar smooth muscle and less coronary blood vessel dilation). b1 (++) activation increases CO

Front 9

Clinical use of norepinephrine?

Back 9

hypotension, HF

Front 10

Toxicity of norepinephrine?

Back 10

same as epinephrine + reflex bradycardia increased risk of Cardiac ischemia (less coronary vessel dilation with increased CO inc. O2 demand)

Front 11

Receptor specificity for dopamine?

Back 11

D1=D2 >>>b>>>a

Front 12

Mechanism of action of dopamine?

Back 12

low dosess--potent dopamine receptor agonist--dilation of renal and coronary vascular beds, medium doses speeds heart rate (beta), high doses produces vasoconstriction (a-R), also causes release of catecholamines

Front 13

Clinical uses of dopamine?

Back 13

hypotension, HF, especially useful for cardiogenic and hypovolemic shock which are associated with low cardiac output and compromised renal function

Front 14

Toxicity of dopamine?

Back 14

same as epinephrine + reflex bradycardia increased risk of Cardiac ischemia (less coronary vessel dilation with increased CO inc. O2 demand)

Front 15

Receptor specificity for fenoldopam?

Back 15

D1>>D2

Front 16

Mechanism of action of Fenoldopam?

Back 16

related to dopamine, similar effects on D-R, stimulates a2 receptors, presynaptic sympathetic inhibition

Front 17

Clinical uses of Fenoldopam?

Back 17

hypertension (severe)

Front 18

Toxicity of Fenoldopam?

Back 18

same as epinephrine + reflex bradycardia increased risk of Cardiac ischemia (less coronary vessel dilation with increased CO inc. O2 demand)

Front 19

Receptor specificity for Isoproterenol?

Back 19

b1=b2 >>>>>>>a (Is bein)

Front 20

MOA for Isoproterenol?

Back 20

+ inotropy and chronotropy, vasodilation (lowers PVR)

Front 21

Clinical use for Isoproterenol?

Back 21

bradycardia (atropine-resistant) or heart block

Front 22

Toxicity for Isoproterenol?

Back 22

palpitations, tachycardia, headache, flushed skin, cardiac ischemia and arrhythmias

Front 23

Receptor specificity for Dobutamine?

Back 23

b1>b2>>>>>a

Front 24

MOA for Dobutamine?

Back 24

b1 agonist (+++) with mixed a-agonist/antagonist (+/-) activity (depends on enantiomeric form), more prominent inotropic and chronotropic effects (small change in PVR)

Front 25

Clinical use for Dobutamine?

Back 25

HF

Front 26

Toxicity for Dobutamine?

Back 26

palpitations, tachycardia, headache, flushed skin, cardiac ischemia and arrhythmias