Adrenergic Drugs Flashcards
What receptors are activated for epinephrine?
alpha-1, alpha-2
beta 1,2,3
B1 = B2 = B3 > a2
what receptors are activated for NE?
alpha1, alpha2, beta 1
Alpha»_space;> Beta
What receptor is activated for Phenylephrine?
alpha-1
What receptors are activated for Clonidine and Apraclonidine?
alpha-2
What receptors are activated for Isopreternol?
Beta 1,2,3
What receptor is activated in Dobutamine?
Beta 1 selective agonist
What receptor is activated for Albuterol/Salmeterol
Beta 2 selective agonist
What receptors are activated for Dopamine?
D1, D2
Ephedrine (dopamine)
direct and indirect acting
Tyramine, Methyldopa, Cocaine, Amphetamine
Indirect-acting (mainly, but is mixed)
What is the MOA Indirect- acting adrenergic drugs?
1) stimulation of release of catecholamines from adrenergic nerve endings
a. facilitated exchange diffusion
b. false-transmitter concept
2) inhibition of re-uptake of catecholamines already released (some indirect acting adrenergic drugs inhibit the re-uptake of NE by blocking the amine transport system)
Role of Reflex Homeostatic adjustments– Epinephrine:
Systolic BP
Diastolic BP
Increases Systolic BP
Decreases Diastolic BP
Role of Reflex Homeostatic adjustments– Epinephrine:
Direct action on cardiac rate
Increased
Role of Reflex Homeostatic adjustments– Epinephrine:
Reflex action on cardiac rate
Decresaed
Role of Reflex Homeostatic adjustments– Epinephrine:
Final effect on cardiac rate
Increased
Role of Reflex Homeostatic adjustments– NE
Systolic BP
Diastolic BP
Increases both
Role of Reflex Homeostatic adjustments– NE
Direct action on cardiac rate
Increases
Role of Reflex Homeostatic adjustments– NE
Reflex action on cardiac rate
DECREASES
Role of Reflex Homeostatic adjustments– NE
Final effect on cardiac rate
decreases
Role of Reflex Homeostatic adjustments– ISO
Systolic BP
Diastolic BP
Increases Systolic
Decreases Diastolic
Role of Reflex Homeostatic adjustments– ISO
Direct action on cardiac rate
increases
Role of Reflex Homeostatic adjustments– ISO
Reflex action on cardiac rate
increases
Role of Reflex Homeostatic adjustments– ISO
Final effect on cardiac rate
INCREASES
Pharmacodynamics EPI (Heart)
cardiac = B1 (mostly) some B2
Increased HR
Increased conduction
Increased contractility
DECREASED cardiac efficiency
Pharmacodynamics EPI (Vessels):
Vasoconstriction predominates where?
Vasodilation predominates where?
Vasoconstriction: Cutaneous, GI, Renal Vessels (alpha-1)
Vasodilation: Skeletal muscle & Liver (Beta-2)
Pharmacodynamics EPI (Blood Pressure):
Low doses EPI cause increase or increase in bp?
Decrease (Vasodilation B2)
Pharmacodynamics EPI (Blood Pressure):
Intermediate doses EPI cause increase or increase in bp?
Systolic BP increases (due to rise in CO)
Diastolic BP decreases (B2 receptor mediated vasodilation usually predominates)
Mean BP is usually slightly elevated
Pharmacodynamics EPI (Blood Pressure):
High doses EPI cause increase or increase in bp?
both systolic and diastolic BP INCREASE (B1)
Pharmacodynamics EPI (Respiratory Sys):
Effects on smooth muscle, mucociliary clearance?
bronchial smooth muscle relaxation
INCREASED mucociliary clearance
Pharmacodynamics EPI (GI)
effects on smooth muscle, peristalsis, sphincters?
Relaxation of smooth muscle (a2 on cholinergic reduces ACh release, activaiton of b2 receptors directly relaxes smooth muscle)
decreased GI peristalsis
Contraction of sphincters (a1)
Pharmacodynamics EPI (GU)
contraction of trigone and internal sphincter, relaxation of pregnant uterus
Pharmacodynamics EPI (CNS):
lacks direct central effects (bc epi doesnt enter CNS)
Pharmacodynamics EPI (Eye):
does EPI cause mydriasis or ____.
Does it decrease or increase intraocular pressure?
contraction of radial muscle of iris –> mydriasis
DECREASED intraocular pressure
Pharmacodynamics EPI (skeletal muscle)
causes what in skeletal muscle?
tremor (B2 accelerates sequestration of cystolic Ca and enhances discharge of muscle spindles)
increased K+ uptake into cell (B2 activation)
Pharmacodynamics EPI (metabolic effects):
epinephrine causes hyper or hypoglycemia?
hyperglycemia:
1) inhibition of insulin secretion
2) stimulation of glycogenolysis and gluconeogenesis
3) stimulation of glucagon secretion
+
increased lipolysis (B3)
What is the Route of Administration for Epinephrine?
Parenteral ONLY! (0% oral bioavailability)
What is the half life of epinephrine?
2 minutes
What are the adverse effects of EPI in the CNS?
restlessness, throbbing HA, dizziness, tremors, weakness, dyspnsea
cerebral hemorrhage (rare- from increased BP)