Review Exam ANS Pharmacology Flashcards
Rank Drugs from Highest to Lowest affinity for Alph-1 R:
Dopamine, Isoproterenol, Dobutamine, Norepinephrine, phenylephrine, Epinephrine, Ephedrine
- Norepinephrine
- Phenylephrine
- Epinephrine
- Dopamine
- Ephedrine
- Dobutamine
- Isoproterenol
N P E D E D I
Hemodynamic effects of HIGH DOSE NE include?
Decreased Cardiac Output
What type of catecholamine is NE?
Natural occurring catecholamine
What receptors does NE have an affinity for?
Dose-dependent A1, A2, B1
Receptor affinity for LOW dose NE?
B1
Low dose NE Effects?
B1- Increased Contractility, CO, BP
Receptor affinity for HIGH dose NE?
A1
High dose NE effects?
Increase SVR Decreased HR (BBR)
*masks B1 effects
NE is an ideal drug for?
LOW SVR states
-Sepsis or Post CPB HoTN d/t LOW after load
Avoid NE in which settings?
Cardiogenic Shock
-Increases MVO2 & SVR
What risk can peripheral administration of NE cause?
Extravasation of NE can cause tissue necrosis
should be administered via CL
How do you Tx NE extravasation at peripheral site?
PhenTolAmine – 2.5 - 10 mg in 10mL diluent
-vasodilates affected region
OR
Stellate Ganglion Block on affected side
-counteracts vasoconstriction by increasing BF
Key Drug interactions for NE
MAO inhibitors (MAOi) Tricyclic antidepressants (TCA)
MAOi – decreased NE clearance –> excessive SNS stimulation
TCA- reduced NE reuptake –> Excessive SNS stimulation
Infusion rate: Low Dose Epi
0.01 - 0.03 mcg/kg/min
Infusion rate: Intermediate Dose Epi
0.03 - 0.15 mcg/kg/min
Infusion rate: High Dose Epi
> 0.15 mcg/kg/min
Effects of Low Dose Epi
Dominating receptor: Non-selective Beta
- B1 –> increase HR + contractility
- B2–> vasodilation skeletal muscles
net effect:
increased CO, decreased SVR, slight decrease BP, wide PP
Effects of Intermediate Dose Epi
Mixed beta & alpha effects
Effects of High Dose Epi
Dominating receptor: Alpha
Increased SVR
Common side effects of High Dose Epi
SVT
*limits usefulness of high dose epi
Rank affinity of dopamine vs. Beta vs. Alpha at adrenergic receptors?
DA > Beta > Alpha
Infusion rate: Low Dose Dopamine
Renal: 1 -2 mcg/kg/min
Infusion rate: Intermediate Dose Dopamine
Cardiac: 2-10 mcg/kg/min
Infusion rate: High Dose Dopamine
Vasopressor: 10-20 mcg/kg/min
Effects of LOW Dose Dopamine
DA1 (post) Vasc, DA2 (pre) Renal
DA1- vasodilation in renal
DA2-inhibits NE release from presynaptic NT
Net effect: Increased RBF, UOP
Effects of Intermediate Dose Dopamine
Beta receptor dominate
- Increased: HR, contractility, CO
- same: BP
Which dopamine dose (low, intermediate, high) for CHF?
Intermediate
Effects of High Dose Dopamine
Alpha receptor dominates
Alpha > beta & DA
Resembles High dose NE
Isoproterenol and CPP
decreases CPP
Isoproterenol- decreases SVR
- SVR decrease can drop DBP–> impair CPP
CPP calculation?
CPP = AoDB - LVEDP (APEX)
AoDB- Aortic Diastolic BP
CPP = DBP - LVEDP (Edwards)
Range: 60-80 mmHg
Isoproterenol and Sepsis
AVOID in Sepsis
Isoproterenol causes:
- severe dysrhythmias
- tachycardia
- Vasodilates nonessential vascular beds (muscle/skin)
Clinical uses for Isoproterenol?
- Chemical PM
- Heart transplant
- Bronchoconstriction
- Cor Pulmonale
2 organic key components in Catecholamines
- Catechol Nucleus (benzene ring w/ hydroxyl group 3,4
2. Amine side chain
Organic size rank of Catecholamines (largest to smallest)
Dobutamine > Isoproterenol > Epi > NE > Dopa
How many Benzene rings does Dobutamine have?
Dobutamine is the ONLY one that has TWO benzene rings
