Adrenergic Drugs Flashcards Preview

Mini II > Adrenergic Drugs > Flashcards

Flashcards in Adrenergic Drugs Deck (95):
1

What receptors are activated for epinephrine?

alpha-1, alpha-2
beta 1,2,3

B1 = B2 = B3 > a2

2

what receptors are activated for NE?

alpha1, alpha2, beta 1

Alpha >>> Beta

3

What receptor is activated for Phenylephrine?

alpha-1

4

What receptors are activated for Clonidine and Apraclonidine?

alpha-2

5

What receptors are activated for Isopreternol?

Beta 1,2,3

6

What receptor is activated in Dobutamine?

Beta 1 selective agonist

7

What receptor is activated for Albuterol/Salmeterol

Beta 2 selective agonist

8

What receptors are activated for Dopamine?

D1, D2

9

Ephedrine (dopamine)

direct and indirect acting

10

Tyramine, Methyldopa, Cocaine, Amphetamine

Indirect-acting (mainly, but is mixed)

11

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)

12

Role of Reflex Homeostatic adjustments-- Epinephrine:

Systolic BP
Diastolic BP

Increases Systolic BP
Decreases Diastolic BP

13

Role of Reflex Homeostatic adjustments-- Epinephrine:

Direct action on cardiac rate

Increased

14

Role of Reflex Homeostatic adjustments-- Epinephrine:

Reflex action on cardiac rate

Decresaed

15

Role of Reflex Homeostatic adjustments-- Epinephrine:

Final effect on cardiac rate

Increased

16

Role of Reflex Homeostatic adjustments-- NE

Systolic BP
Diastolic BP

Increases both

17

Role of Reflex Homeostatic adjustments-- NE

Direct action on cardiac rate

Increases

18

Role of Reflex Homeostatic adjustments-- NE

Reflex action on cardiac rate

DECREASES

19

Role of Reflex Homeostatic adjustments-- NE

Final effect on cardiac rate

decreases

20

Role of Reflex Homeostatic adjustments-- ISO

Systolic BP
Diastolic BP

Increases Systolic
Decreases Diastolic

21

Role of Reflex Homeostatic adjustments-- ISO

Direct action on cardiac rate

increases

22

Role of Reflex Homeostatic adjustments-- ISO

Reflex action on cardiac rate

increases

23

Role of Reflex Homeostatic adjustments-- ISO

Final effect on cardiac rate

INCREASES

24

Pharmacodynamics EPI (Heart)

cardiac = B1 (mostly) some B2

Increased HR
Increased conduction
Increased contractility
DECREASED cardiac efficiency

25

Pharmacodynamics EPI (Vessels):

Vasoconstriction predominates where?
Vasodilation predominates where?

Vasoconstriction: Cutaneous, GI, Renal Vessels (alpha-1)

Vasodilation: Skeletal muscle & Liver (Beta-2)

26

Pharmacodynamics EPI (Blood Pressure):

Low doses EPI cause increase or increase in bp?

Decrease (Vasodilation B2)

27

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

28

Pharmacodynamics EPI (Blood Pressure):

High doses EPI cause increase or increase in bp?

both systolic and diastolic BP INCREASE (B1)

29

Pharmacodynamics EPI (Respiratory Sys):

Effects on smooth muscle, mucociliary clearance?

bronchial smooth muscle relaxation

INCREASED mucociliary clearance

30

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)

31

Pharmacodynamics EPI (GU)

contraction of trigone and internal sphincter, relaxation of pregnant uterus

32

Pharmacodynamics EPI (CNS):

lacks direct central effects (bc epi doesnt enter CNS)

33

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

34

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)

35

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)

36

What is the Route of Administration for Epinephrine?

Parenteral ONLY! (0% oral bioavailability)

37

What is the half life of epinephrine?

2 minutes

38

What are the adverse effects of EPI in the CNS?

restlessness, throbbing HA, dizziness, tremors, weakness, dyspnsea

cerebral hemorrhage (rare- from increased BP)

39

What are the adverse effects of EPI in CVS?

HPT, pallor

anginal pain (in patients with CHD), sinus tachy, ventricular arrhythmias

pulmonary edema (rare)

40

Therapeutic uses of Epinephrine

serious acute hypersensitivty rxn (anaphylaxis, angioedema)

Cardiac arrest (a1 receptor activation)

prevention of surgical bleeding (given topically for superficial wounds)

to retard absorption of local anesthetics



41

in cardiac arrest what receptor does epi activate to increase venous return?

alpha 1

42

What is the final effect of NE on the heart?

decrease in HR

43

What is NE action on the Vessels?

Vasoconstriction predominates in all vascular beds (except coronary and pulmonary where autoregulatory actions override direct vasoconstrition effect of NE)

44

Is BP increased or decreased when EPI is given?

increased (but pulse pressure doesn't change)

45

therapeutic uses of NE?

hypotension and vasodilatory shock (due to spinal trauma, spinal anesthesia, sepsis)

with local anesthetics (to retard their absorption)

46

What is the MOA and pharmacological effect of dopamine at low doses?

activation of D1 receptors

vasodilation in kidney, mesenteric and coronary beds

inhibition of Na+ reabsorption in PCT

(overall --> increased diuresis!)

47

What is the MOA and pharmacological effect of dopamine at intermediate doses?

activation of B1 receptors + release of NE from nerve terminals

increased stroke volume and HR

48

What is the MOA and pharmacological effect of dopamine at high doses?

activation of a1 and d2

increased systemic vascular resistance, nausea, and vomiting

49

what is the route of administration of dopamine?

IV infusion only

50

half life of dopamine

2 mins

51

therapeutic uses of dopamine

cardiogenic, neurogenic and septic shock

52

mechanism of action of a1 receptor agonist

Gq --> PLC

1) IP3 --> inc. Ca2+ --> Increased contraction of vascular smooth muscle

2) DAG --> Protein kinase C --> Inc. Ca+ --> increased contraction of vascular smooth muscle

53

effects on cardiovascular system of alpha1 agonist

increase in blood pressure associated with bradycardia because of activation of baroreceptor reflex

54

which class of drugs can cause rebound congestion (when used as nasal decongestant) as an adverse effect?

phenylephrine (a1 agonist)

55

therapeutic uses of alpha 1 agonists

aka. phenylephrine

postural hypotension

nasal or ocular decongestant

mydriatics

local vasoconstrictor (i.e in epistaxis)

to prolong action of local anesthetics

56

drugs that act on a2 and imidazoline receptors

clonidine
apraclonidine

57

drugs that act on a2 receptors

Guanfacine
Tizanidine

58

MOA of clonidine

1) activation of PREsynaptic a2 receptors located in nucleus of tractor solitarius in rostral ventrolateral medulla

2) activation of non-adrenergic binding sites-- imidazoline receptors

Overall-- decreased firing of reticulospinal tract which decreases central adrenergic tone (main antihypertensive MOA of clonidine)

59

effects of a2 selective agonists on CVS

i.e. clonidine

1) low/intermediate-- hypotension

2) high-- Hypertension

60

effects of a2 agonists on CNS

i.e. clonidine

craving-reducing effects in addicts
sedative effects
analgesic effects

61

half life clonidine

12 hours

62

therapeutic uses of a2 agonists

i.e. clonidine

1)HTN (second choice drugs)
2)open angle glaucoma
3)withdrawal from tobacco, alc or opiods
4)preanesthetic medication to induce preoperative sedation and reduce requirement for anesthetic
5) severe pain
6) diabetic neuropathy
7) neuropsychiatric disorders (Tourettes, ADHD, autism)

63

effects of B-agonists on the Heart

i.e. Isoproterenol

Increased HR (tachycardia)

64

effects of B-agonists on vessels

i.e. isoproterenol

b2 mediated vasodilation predominates in all vascular beds

65

effects of B-agonists on BP

i.e. Isoproterenol

systolic BP remains unchanged or increases

Diastolic BP decreases sharply

Mean BP usually falls

66

administration of isoproterenol

IV infusion only

67

therapeutic uses of isoproterenol

emergency situations where heart contractility is low and HR is slow yet peripehral resitance is high (i.e. Cardiac surgery)

Torsade de Pointes (polymorphic Vtach)

68

MOA of increased cardiac contractility of B1 receptor agonist:

(i.e. Isoproterenol)

Gs --> Adenylyl cyclase --> inc. cAMP --> Protein Kinase A:

1) increased phosphorylation of troponin C
2) inc. opening of voltage gated Ca2+ channels
3) inc. Ca2+ reuptake by SR

69

MOA of increased cardiac conduction by B1 receptor agonist

Gs --> adenylyl cyclase --> inc. cAMP --> protein kinase A --> opening Na+ channels --> depolarization of cell membranes of SA node, AV node and Ventricular conduction system

70

pharmacological effects of dobutamine on the heart

b1 agonist

increase contractility and conduction

71

therapeutic uses of dobutamine?

b1 agonist

Iv infusion to patients with cardiac failure or cardiogenic shock

72

effects of albuterol/salmeterol on respiratory system

b2 agonist

bronchodilation, enchanced mucociliary clearance, suppression of release of inflammatory mediators (leukotrienes, histamine), reduction of microvascular permeability

73

administration of albuterol/salmeterol

inhalation (main route), po, sc

74

MOA of smooth muscle relaxation by B2 receptor agonists

i.e. albuterol

Gs --> adenylyl cyclase --> inc. cAMP --> protein kinase A:

1) Inc. Ca2+ efflux --> decreased smooth muscle contraction
2) inc. inactivation of myosin-light-chain kinase --> dec. phosphorylation of myosin light chains --> decreased smooth muscle contraction

75

adverse effect of B2 receptor agonist on CNS

tremor, muscle cramps

76

Therapeutic uses of albuterol/salmeterol

b2 agonist

1) asthma
2)COPD
3)Hyperkalemia
4) premature labor

77

Tyramine

direct or indirect adrenergic drug?

Indirect acting adrenergic drug

78

MOA of tyramine

false transmitter taken up by adrenergic neurons where it is transformed into octopamine

79

Pharmakokinetics of tyramine

normal byproduct of tyrosine metabolism in body

inactive if ingested because of a very large fisrt-pass effect

80

clinical uses of tyramine

localize lesion of sympathetic nerves

81

MOA of Methyldopa

(indirect adrenergic drug)

false NT which is taken up by adrenergic neurons where it is transformed into methylnorepinephrine (a2 receptor agonist)

activation of central a2 receptors by methylnorepinephrine reduces central adrenergic tone

82

MOA of amphetamines

indirect acting adrenergic drug

stimulation of release of monoamines (NE, dopamine, serotonin)-- peripherally and centrally

83

MOA of cocaine

indirect-acting adrenergic drug

blockade of reuptake of monoamines (NE, dopamine, and serotonin)

84

Ephederine MOA

activation of a1, a2, b1 and b2 receptors
enhanced release of NE from adrenergic neurons

it is an over the counter ingredient in decongestants

85

what drugs would you give for cardiogenic shock?

dobutamine, dopamine

86

what drugs would you give for vasodilatory shock (i.e. neurogenic, septic?)

NE, Phenylephrine, dopamine

87

What drugs would you give for anaphylactic shock, CPR?

epinephrine

88

what drug would you give for torsade de pointes?

isoproterenol

89

what drug would you give for HTN?

clonidine or methyldopa

90

what drugs would you give for local anesthesia (to cause local vasoconstriction?)

epinephrine, NE

91

what drugs would you give for asthma, copd?

b2 selective agonists or epinephrine

92

what drugs woudl you give for anaphylaxis or angiodema?

epinephrine

93

what drug would you give for open anlge glaucoma?

apraclonidine

94

what drug woudl you give for narcolepsy, ADHD, weight reduction?

amphetamines and congeners

95

what drug woudl you give for withrdawal from tobacco, alcohol or opiods? or Tourettes syndrome, ADD, etc.

clonidine