Heart Failure Drugs

Question 1

preload

Answer 1

volume of blood in the ventricles at the end of diastole which stretches the ventricles

Question 2

What drugs are used to reduce preload?

Answer 2

DIURETICS (and sometimes nitroprusside/nitroglycerin)

Question 3

Loop diuretics MOA

Answer 3

inhibit the Na/K/Cl cotransporters in the thick ascending limb of the Loop of Henle

Question 4

2 Examples of Loop Diuretics

Answer 4

1) Furosemide (Lasix)
2) Torsemide

Question 5

Which is more potent - furosemide or torsemide?

Answer 5

torsemide (10-20x) - used more in end stage or refractory cases of heart failure

Question 6

Thiazide diuretic MOA

Answer 6

inhibits the reabsorption of Na and Cl in the distal tubule

Question 7

Main side effects of Diuretic Therapy?

Answer 7

dehydration and electrolyte abnormalities

Question 8

Spironolactone

Answer 8

competitively antagonizes aldosterone by downregulating NaK pump and therefore blocking Na reabsorption in the distal convoluted tubule

Question 9

Why is spironolactone considered a weak diuretic?

Answer 9

not that much sodium is really reabsorbed in the collecting duct and that’s its main MOA

Question 10

Inotrope

Answer 10

agent which alters the force of heart muscle contractility

Question 11

Negative Inotrope Definition and Two Categories

Answer 11

decreasing the force of muscular contractions
1) beta blockers
2) calcium channel blockers

Question 12

Clinical Scenarios for Negative Inotropes

Answer 12

Hypertrophic Obstructive Cardiomyopathy, Stenoses, tachyarrhythmias

Question 13

Positive Inotrope Definition and Three Examples

Answer 13

Increase the strength of muscular contraction; also reduces mitral regurgitation and pulmonary edema
1) Dobutamine
2) Pimobendan
3) Digoxin

Question 14

5 Goals of Positive Inotrope

Answer 14

IMPROVE:
1. Contractility
2. Cardiac output
3. Blood pressure
4. Clinical signs
5. QOL

Question 15

Which positive inotrope is given IV?

Answer 15

dobutamine

Question 16

Pimobendan

Answer 16

the first line therapy for heart failure - an oral medication that does NOT cause significantly increased calcium!

Question 17

Dobutamine

Answer 17

a continuously administered IV medication (positive inotrope) for severe cases of heart failure

Question 18

Cardiac Output equation

Answer 18

heart rate times stroke volume

Question 19

Pimobendan MOA

Answer 19

inhibits phosphodiesterase III making it a balanced arterial and venous vasodilator, making the heart more SENSITIVE without increasing levels of calcium

Question 20

Phosphodiesterase Inhibtors

Answer 20

prevent conversion of cAMP to AMP; more cAMP means more contractility

Question 21

Afterload

Answer 21

the pressure the ventricle must overcome to circulate blood (left –> aorta or right –> pulmonary artery)

Question 22

Is afterload increased or decreased when blood pressure is high?

Answer 22

increased

Question 23

Is afterload increased or decreased during vasoconstriction?

Answer 23

increased

Question 24

Ideal systemic blood pressure?

Answer 24

110-130mmHg

Question 25

Systemic Afterload Reducers

Answer 25

work on the left side of the heart; Amlodipine, angiotensin receptor blockers (drugs that end in -sartin), and ACE inhibitors (Enalapril, Benazepril, etc)

Question 26

Ideal pulmonary pressure?

Answer 26

15-25mmHg

Question 27

Overlapping mechanisms which control blood pressure?

Answer 27

neuro, renal, vascular, hormonal

Question 28

Beta receptor on the heart?

Answer 28

b1

Question 29

Beta receptor on the lungs?

Answer 29

b2

Question 30

Nucleus solitarius

Answer 30

termination of afferent stimuli (from vagal and glossopharyngeal nerves of the autonomic nervous system) in the medulla

Question 31

baroreceptors

Answer 31

part of the autonomic nervous system and participate in the feedback loop which controls blood pressure

Question 32

In circulation, which is higher under normal conditions - epinephrine or norepinephrine?

Answer 32

epinephrine

Question 33

Amlodipine

Answer 33

calcium channel blocker

Question 34

Sildenafil

Answer 34

stimulates the nitric oxide pathway via inhibiting PDE5; treats pulmonary hypertension

Question 35

RAAS

Answer 35

Renin Angiotensin Aldosterone SYstem

Question 36

End products of RAAS?

Answer 36

aldosterone and angiotensin II

Question 37

How to block RAAS?

Answer 37

ACE inhibitors, angiotensin receptor blockers, spironolactone

Question 38

Side effects of ACE inhibitors?

Answer 38

azotemia

Question 39

Beta blockers are what drugs?

Answer 39

the -olols (like atenolol); helps chill out the sympathetic nervous system