Lecture 20/21 - CHF Drugs Flashcards Preview

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Flashcards in Lecture 20/21 - CHF Drugs Deck (114):
1

What major molecule controls the contractility of the heart?

Calcium

2

What six aspects can be alter cardiac contractility?

Sensitivity to Ca
Amount of Ca released from SR
Amount stored in SR
Amount of trigger Ca
Na/Ca exchanger activity
Intracellular Na concentration

3

What are the four components of cardiac performance?

Preload
Afterload
Contractility
Heart rate

4

What occurs in cardiogenic shock in regards to stroke work?

even with LV filling pressure increasing heart can't counteract with increased work force

5

What are the three aspects of pressure of fluid movement within the capillaries?

Hydrostatic
Colloid
Tissue

6

What is normal transudation pressure?

10 to 15 mmHg

7

Drug type that works on: Decreased CO

Positive inotropic drugs

8

Drug type that works on: Na + Water retention

Diuretics

9

Drug type that works on: RAA system

ACE inhibitors

10

Drug type that works on: Cardiac remodeling

ACE inhibitors + B-blockers

11

Drug type that works on: Congestion + Edema

Diuretics

12

Drug type that works on: Increased venous volume + pressure

Vasodilators

13

Drug type that works on: Increased afterload

Vasodilators

14

What are the nine drug groups that can be used to treat CHF, or other cardiac conditions? (nine)

Diuretic
ACE inhibitors
Calcium sensitizers
Digitalis
Sympathomimetics
Inodilators
Beta blockers
Alpha/Beta blockers
Calcium channel blockers

15

List the drugs: Diuretics

Furosemide
Spironolactone
Hydrochlortiazide

16

List the drugs: ACE inhibitors

"-prils"
Enalapril
Benazepril
Captopril

17

List the drugs: Calcium sensitizer

Pimobendan

18

List the drugs: Digitalis

Digoxin

19

List the drugs: Sympathomimetics

Dobutamine
Dopamine

20

List the drugs: Inodilators

"-nones"
Amrinone
Milrinone

21

List the drugs: Beta Blockers

"-olol"
Atenolol
Propranolol
Metoprolol

22

List the drugs: A/B blockers

Carvedilol

23

List the drugs: Calcium channel blockers

Diltiazem

24

What characterizes CHF?

High cardiac filling pressure -->
Leading to venous congestion + Tissue fluid accumulation

25

Where, in regards to the CHF, does venous congestion occur?

Behind the affected side of the heart

26

What condition normally underlies CHF that can cause further progression of the disease?

Poor contractility

27

What can stimulate compensatory mechanisms to begin in CHF?

Chronic cardiac overload (Volume or Pressure)

28

What are the major signs of left-sided CHF?

Pulmonary venous congestion + edema
Cough + Pulmonary crackles + etc.

29

What occurs with chronic pulmonary venous congestion?

Pulmonary hypertension
Sometimes right sided CHF can begin

30

What are the major consequences of right-sided CHF?

Systemic venous hypertension
Jugular venous distension
Hepatic congestion + Pleural effusion

31

What are the three goals in the treatment of Acute CHF?

Decrease pulmonary edema
Increase CO
Oxygenate patient

32

What is acute CHF characterized by?

Severe cardiogenic pulmonary edema with poor CO
+/- pleural effusion
+/- abdominal effusion

33

What changes with chronic CHF even with medical management?

Even with drugs on board
Will still see pleural effusion + ascites

34

What is a very important medication in Chronic heart failure for support of myocardial function?

Pimobendan

35

What can be given with Pimobendan if CHF is severe?

Digoxin

36

What are two examples of diastolic dysfunction?

Hypertrophic cardiomyopathy
-- and --
Cardiac tamponade

37

What is the treatment for cardiac tamponade?

Pericardiocentesis - to relive the pressure on the heart and allow it to fill normally
No medical management

38

What specific animal tends to suffer from hypertrophic cardiomyopathy the most?

Maine Coon Cats

39

What does hypertrophic cardiomyopathy impair in the heart?

Ventricular filling

40

What is a major overall goal when treating hypertrophic cardiomyopathy?

Slow the heart rate - allows for increased filling time + reduces occurance of ischemia

41

What is a goal of a drug used to treat hypertrophic cardiomyopathy?

Improve cardiac relaxation

42

What medications are most helpful when treating hypertrophic cardiomyopathy?

Furosemide
-- and --
ACEi

43

When would you most use furosemide in treating hypertrophic cardiomyopathy?

When CHF begins to develop

44

Why are diuretics used to treat CHF?

Control edema + effusion

45

Describe: Furosemide

Loop-diruetic
Used mostly in cases of cardiogenic edema/effusion

46

What are the recommendations for Furosemide use in chronic HF?

not used as monotherapy

47

What is Furosemide used for in regards to acute CHF?

Sudden onset pulmonary edema

48

What is the primary use of Furosemide in racing horses?

Excercise induced pulmonary hemorrhage

49

What is an adverse effect of Furosemide?

Excessive fluid and/or electrolyte loss

50

Describe: Spironolactone

K-sparing diuretic, little effect in dogs though

51

What are the adverse effects of Spironolactone?

Excess K retention + GI disturbances

52

What are contrindicated uses of Spironolactone?

Hyperkalemic patients
Patients on ACEi + K supplements

53

What specific disease processes is Spironolactone used for?

Chronic refractory HF

54

When is a thiazide diuretic used?

In dogs that have become resistant to furosemide

55

What is occurring biochemically with ACEi?

Inhibits ACE
Decreasing ANGII + Increase Bradykinin

56

Why does bradykinin increase with ACEi?

ACE normally degrades Bradykinin

57

What is a contraindication for ACEi? Why?

Liver insuffiency, ACEi are pro-drugs and need to be metabolized by the liver

58

What are the main benefits of ACEi use?

Reduce neurohormonal activation
-- and --
Art/Venous vasodilation

MAY stop abnormal CV remodeling changes

59

What type of diuretic effect does ACEi have?

Renal Na retention

60

What are the specific therapeutic uses of ACEi?

Chronic management of CHF
Dilated cardiomyopathy
Valvular insufficiency
Hypertrophic cardiomyopathy

61

What disease is ACEi the first drug of choice to treat?

Dogs: Systemic arterial hypertension

62

What adverse effects are seen in ACEi use?

Hypotension + GI upset + Hyperkalemia

63

What happens to treatment regimine if azotemia develops?

Diuretic dose decreased first!
then ACEi is reduced or removed

64

Characteristics: Enalapril

most excreted in kidney
2hr half life

65

Characteristics: Benazepril

Much longer 1/2 in cats (up to a day)
Renal + Hepatic excretion

66

What is pimobendan?

Inotropic drug + Vasodilating properties

67

How does pimpbendan work?

Inhibits phosphodiesterase III = vasodilation
Increase cAMP = Increase L Ca2+ channels
Increase myofiliament sensitivity to Ca

68

What is the therapeutic use for Pimobendan?

CHF --
Dilated cardiomyopathy
Chronic mitral valve disease

69

Pharmokinetics: Pimobendan

>90% protein bound
Excretion through feces
Delay from peak concentration + maximal effect

70

What are the adverse effects of pimobendan?

not many lethargy, diarrhea, dyspnea
Rare: Azotemia

71

What do glycocides contain?

Aglycon
Three digitoxose

72

What plant contains glycosides?

Foxglove

73

What is the main function of Digoxin?

Positive iontropic effect

74

What is the mechanism of action for digoxin?

Bind to Na/K ATPase channel on myocardial membrane
Decrease Na transport leading to increased intracellular Ca

75

What does digoxin have anti-arrhythmic effects towardS?

Supraventicular tachyarrhythmia

76

By what mechanisms does digoxin have anti-arrhythmic effects?

Improves arterial baroreceptor sensitivity
Increased vagal activity

77

What is the primary use for Digoxin when wanted for its anti-arrhythmic effects?

Artrial fibrillations - Dilated cardiomyopathy or MVD

78

What is a contrindiation for digoxin usage?

Cats with hypertrophic cardiomyopathy

79

Why do you see increased serum levels of digoxin with dog and cats that have renal problems?

Reduced body clearance
-- and --
Volume of distribution

80

What does Digoxin bind to mostly in the body? Why is this a problem?

Skeletal muscle
-- if animal has wasting, decreased effect of the drug

81

What is the treatment for digoxin toxicity?

Intravenous K
Lidocaine + Propranolol + Phenytonin
Immunotherapy

82

What is the biggest adverse effect of Digoxin?

Cardiac toxicity

83

What are some arrhythmias that Digoxin stimulate?

Sinus bradycardia
Ectopic ventricular beats
AV block

84

What is the most common arrhythmia due to Digoxin that can cause death?

Ventricular fibrillation

85

What causes a decrease in digoxin absorbtion?

Antacids
Kaolin-pectin
Food

86

How long does it take for Digoxin to reach SS in the blood of: Horse, Dog, and Cat

Horse - 3 days ~
Dog - 7 days
Cat - 10 days

87

What is the main method of excretion of Digoxin?

renal

88

How is Digoxin transported?

Pgp

89

What seven things can increase digialis toxicity?

Hypokalemia
B-antagonist
Calcium channel blockers
Decrease plasma protein
Decrease renal excretion
Altered GI flora
Sensitizing myocardium

90

What are the two ways K interacts with digitalis?

Inhibit each other binding to Na/K ATPase receptor
-- and --
K reduces cardiac automaticity

91

What other compound decreases digitalis toxicity?

Mg

92

What compound SHOULD NOT BE GIVEN with digitalis?

Calcium

93

What is the standard drug therapy for heart failure?

Diuretics
ACEi
Pimobendan

94

What breaks down cAMP?

PDE

95

What does cAMP phosphorylate?

PKA + CREB

96

What creates cAMP, what does it make it from?

Adenylyl cyclase
Uses ATP

97

Drug for goal of therapy: Reduced preload

Diuretic
-- and --
Venodilator

98

Drug for goal of therapy: Reduced afterload

Arteriodilator

99

Drug for goal of therapy: Increased contractility

Inotropic drug

100

Drug for goal of therapy: Reduced energy expenditure

B-adrenergic antagonist

101

What CHF effect causes the need for reduced preload?

Increased BV + Venous tone

102

What CHF effect causes the need for reduced afterload?

Increased Aortic impedance + Arterial contriction

103

What CHF effect causes the need for increased contractility?

Ventricular dilation + Reduced pumping force

104

What CHF effect causes the need for reduced energy expenditure?

Increase HR due to reflex tachycardia via SNS hyperactivity

105

What drug group can be used to slow HR and reduce myocardial O2 comsumption?

B-blocker

106

What do calcium entry blockers do to the heart?

Coronary + Systemic vasodilation
Enhanced myocardial relaxation

107

What is a good use for a calcium entry blocker, what drug?

Diltiazem
Hypertrophic cardiomyopathy

108

What is contraindicated with diltiazem?

B-blockers

109

What are important myocardial protective agents?

Some B-blocker s
Carvedilol + Metoprolol

110

When do you need myocardial protective agents?

Dilated cardiomyopathy
-- and --
Chronic valve disease

111

How do the inodilators, Amrinone + Milrinone, work?

Inhibit phosphodiesterase III

112

What effects do Amrinone + Milrinone have?

Increase myocardial contractility
-- and --
Vasodilation

113

What are adverse effects of Amrinone + Milrinone?

Worsen ventricular tachyarrhythmias
Reflex tachycardia

114

Which, Amrinone or Milrinone, last the longest?

Amrinone