Adrenergics Flashcards
What receptors does epineprhine target?
Which is it selective for?
α1 = α<span>2</span>; β1 = β2
α effects seen more at higher [c], β effects seen more at lower [c]
What are the expected effects of epineprhine?
Heart:
-increase rate and force of cardiac contraction (increase cardiac output β1)
Vasculature:
-increase systolic BP (A constriction, α1) w/ some diastolic decrease (V dilation β2), no change in MAP
Lung:
-bronchodilation (β2)
Muscle:
-increases potassium uptake (β2)
Liver:
-increases glycogenolysis and gluconeogenesis (β2)
What receptors does norepineprhine target?
Which is it selective for?
General alpha agonist:
α1 = α2 > β1 >> β2
What are the expected effects of norepineprhine?
Heart:
-increased force of contraction (α1)
Vasculature:
-A and V constriction (α1) > increased BP and MAP > reflex bradycardia
What receptors does phenyleprhrine target?
Which is it selective for?
Selective α1 agonist:
α1 > α2 >>>>> β1/2
What are the expected effects of phenyleprhrine?
Eyes:
-mydriasis (dilation) (α1)
ENT:
-mucosal vasoconstriction (α1) -> decongestant
Vasculature:
-SEVERE vasoconstriction (α1) -> increased BP and MAP -> SEVERE reflex bradycardia
What receptors does clonidine target?
Which is it selective for?
Selective α2 agonist:
α2 > α1 >>>>> β
What are the expected effects of clonidine?
Brain:
- decreased activity in vasomotor center -> bradycardia and decreased BP
- decreased sympathetic response
What receptors does isoproterenol target?
Which is it selective for?
Non-selective β agonist:
β1 = β2 >>>> α
What are the expected effects of isoproterenol?
Heart:
-increased force and rate of contraction (increased cardiac output β1)
Vasculature:
-vasodilation (β2) -> decreased diastolic BP
Lungs:
-bronchodilation (β2)
What receptors does dobutamine target?
Which is it selective for?
Selective β1 agonist:
β1 > β2, α1
Has selective α1 activity
What are the expected effects of dobutamine?
Heart
- increased force of contraction (β1)
- slight increase in rate (β1 dampened by α1?)
- increased cardiac output
What receptors does albuterol target?
Which is it selective for?
Selective β2 agonist:
β2 > β1 >>>> α
What are the expected effects of albuterol?
Lungs:
broncodilation (β2)
What does cocaine do?
Blocks dopamine and NE reuptake from synaptic cleft -> adrenergic effect
What does phenelzine do?
Inhibits MAO -> adrenergic effect
What does selegine do?
Inhibits MAO -> adrenergic effect
What do amphetamines do?
Increase release of dopamine and NE -> adrenergic effect
What does methylphenidate do?
Increase release of dopamine and NE -> adrenergic effect
*Ritalin
What does ephedrine do?
Direct receptor agonist and increases release of dopamine and NE
What does tyramine do?
Increases release of dopamine and NE
Unable to cross BBB and therefore not used as a drug.
Used diagnostically to evaluate peripheral adrenergic function (increases SBP)
What adrenergics would be most effective in treating acute hypotensive emergencies?
- norepinephrine (non-selective α agonist, increased force of contraction and vasoconstriction) (reflex bradycardia)
- phenylephrine (selective α1 agonist significant increase in vasoconstricton) (reflex bradycardia)
What adrenergics would be most effective in treating chronic hypotension?
-Ephedrine (increase release of dopamine/NE and direct receptor agonist)
What adrenergics would be most effective in treating cardiogenic shock?
-dobutamine (selective β1 agonist, increased force and rate of contraction)
What adrenergics would be most effective in treating hypertension?
Clonidine (α2 agonist, depression of vasomotor center)
What adrenergics would be most effective in treating a complete AV block or cardiac arrest?
- epinephrine (α and β agonist, increased cardiac output and increased conduction velocity at AV node)
- isoproteronol (non-selective β agonist, increased cardiac output)
What adrenergics would be most effective in treating depression?
-phenelzine and selegine (MAO inhibitors)
What adrenergics would be most effective in treating asthma?
-albuterol (selective β2 agonist, bronchodilation)
What adrenergics would be most effective in treating congestion of mucous membranes?
- phenylephrine (selective α1 agonist, vasoconstricion of vasculature in mucous membrane)
- ephedrine
What adrenergics would be most effective in treating anaphylaxis?
-epinephrine (α and β agonist, increased cardiac output and bronchodilation)
What adrenergics would be most effective in facilitating retinal examinations?
-phenylephrine (selective α1 agonist, mydriasis/pupilary dilation)
What adrenergics would be most effective in treating glaucoma?
-selective α2 agonists (decrease aqueous humor production from ciliary body)
