Adrenergic Agonists Flashcards Preview

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Flashcards in Adrenergic Agonists Deck (35):
1

Epinephrine at low doses activates what receptors?

B1 and B2. Causes increased HR ad CO, vasodilation. Increased systolic BP and decreased diastolic BP. Bronchodilation.

2

Epinephrine at high doses activates what receptors?

A1, A2, B1, B2. Net effect increase HR and CO, increase systolic and diastolic BP. Increase MAP and TPR from A1/A2 activation of vasoconstriction.

3

Epinephrine toxicity?

Arrhythmias, cerebral hemorrhage, pulmonary edema, anxiety

4

Norepinephrine physiological effects

Activates A1, A2, B1. Increase in CO due to increased contractility (B1). Increase in MAP (systolic and diastolic) due to A1 activation. Decrease in HR as a baroreceptor reflex response.

5

Norepinephrine toxicity

Ischemia

6

Norepinephrine indications?

Shock

7

Epinephrine indications?

Bronchospasm, anaphylaxis, cardiac arrest

8

Dopamine physiological effects at low doses?

Activate D1 and B1 receptors. Vasodilation in renal and splanchnic circulations (decrease in TPR due to D1 activation). Increase in HR and CO due to B1 activation.

9

Dopamine physiological effects at high doses?

Activates A1, A2, B1 receptors. Overall increase in MAP, TPR, and CO.

10

Dopamine toxicity at low and high doses?

Low dose toxicity: hypotension.
High dose toxicity: ischemia

11

Dopamine indications?

Cardiogenic shock

12

Isopreterenol physiological effects?

Nonselective Beta agonist. Activate B1 receptors to increase HR, CO, systolic BP. Activate B2 to cause vasodilation, decrease in TPR. Bronchodilation caused by B2 activation.

13

Isoproterenol Toxicity

Tachyarrhythmias

14

Isoproterenol Indications

Bradycardia or heart block when TPR is already too high

15

Isoproterenol Contraindications

Angina with arrhythmias

16

Dobutamine physiological effects

Selective B1 agonist. Increase HR and increase CO.

17

Dobutamine indications

Short term Rx for cardiogenic shock or CHF

18

Dobutamine toxicity

Hypotension (excess Dobutamine will begin to activate B2 receptors. Arrhythmias.

19

Terbutaline and Albuterol Physiological effects

Selective B2 agonists. Bronchodilation and uterine relaxation.

20

Terbutaline and Albuterol Indications

Bronchospasm and COPD

21

Terbutaline and Albuterol Toxicity

Muscle tremor
Tachycardia (B1)
Tolerance

22

Phenylephrine Physiological effects

Selective A1 agonist. Vasoconstriction (A1). Decrease in HR (baroreceptor reflex). Pupillary dilation (A1 activation- mydriatic agent). Decrease bronchiole and sinus secretions.

23

Phenylephrine Toxicity

Hypertension

24

Phenylephrine Indications

Hypotension during anasthesia
Supraventricular tachycardia
Mydriatic agent in ophthalmology
Nasal congestion

25

Clonidine Physiological Effects

Selective A2 agonist. Causes acute vasoconstriction (increase in BP), then long term decrease in BP due to negative feedback on presynaptic neurons in the CNS.

26

Clonidine Toxicity

Dry mouth.
Hypertensive crisis if withdrawing from medication --> get excess sympathetic activation after A2 inhibition in the CNS.

27

Clonidine Indications

Hypertension due to sympathetic activation

28

What are the indirect acting sympathomimetics? Basically, how do they function physiologically?

Amphetamine
Methamphetamine
Methylphenidate
Ephedrine
Pseudoephedrine
Tyramine

Either increase release of endogenous catecholamines or decrease reuptake of endogenous catecholamines.

29

Physiological effects of indirect acting sympathomimetics?

Increased TPR and MAP (A1, A2)
Positive inotropic and chronotropic effects (B1)
CNS Stimulant
Anorexia

30

Toxicity of indirect acting sympathomimetics

Tachycardia, anxiety

31

Indications of indirect acting sympathomimetics

ADD, narcolepsy, nasal congestion

32

Contraindications of indirect acting sympathomimetics

Prior history of drug abuse
Patient has taken a monoamine oxidase inhibitor in the last two weeks.
Hypertension

33

Basic function amphetamine

Reverse monoamine reuptake transporter.

34

Basic functions Methylphenidate (Ritalin)

Dopamine reuptake inhibitor
Increase attention

35

Basic functions Ephedrine

stimulate release of catecholamines and some direct effect in activating adrenergic receptors

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