Drugs For Heart Failure (Kruse)

Question 1

What are some adverse effects of loops?

Answer 1

HypoK
Alkalosis
Sulfonamide hypersensitivity (not ethacrinic acid)

Question 2

This cardiac glycoside is used in the tx of heart failure, tachyarrhythmias, and shock. It is well absorbed and widely distributed

Answer 2

Digoxin

Question 3

What is the MOA of digoxin?

Answer 3

Inhibits membrane-bound Na/K ATPase and increase myocardial contractility (50-100% in individuals with HF)

Question 4

Digoxin-induced elevated intracellular Ca increases the activity of Ca-dependent ___ channels.

Answer 4

K

Increased Ca-dependent K channel activity promotes K efflux and a more rapid repolarization

Question 5

The most common cardiac manifestation of digoxin toxicity is ___

Answer 5

Arrhythmia

If allowed to progress, the tachycardia may deteriorate into fibrillation that could be fatal unless corrected

Question 6

At toxic doses of digoxin, what occurs in the atrial muscle?

Answer 6

Decreased refractory period

Arrhythmias

Question 7

At toxic doses of digoxin, what occurs at the AV node?

Answer 7

Decreased refractory period

Arrhythmias

Question 8

At toxic doses of digoxin, what occurs in the purkinje system and ventricular muscle?

Answer 8

Extrasystoles
Tachycardia
Fibrillation

Question 9

Describe the ECG findings when digoxin is effective at a therapeutic, non-toxic dose:

Answer 9

Increased PR interval

Decreased QT interval

Question 10

At high doses, what type of drug (or drug name) can potentiate the toxic effects of digoxin?

Answer 10

Furosemide (loop diuretic)

Question 11

Digoxin and K bind to competing sites on the ___

Answer 11

Na/K ATPase

Question 12

What class of agents can increase both the force of heart contraction and produce vasodilation?

Answer 12

Bipyridines

i.e., Milrinone

Question 13

Milrinone is a ___

Answer 13

Bipyridine

Question 14

What is the MOA of bipyridines?

Answer 14

Cause selective inhibition of PDE3 phosphodiesterase enzyme (PDE3 degrades cAMP)

Question 15

What are bipyridines approved for?

Answer 15

SHORT-TERM support of circulation in ADVANCED HF

Chronic tx does not show improvement in quality or length of life and may increase mortality

Question 16

What is the 1st step in the tx of heart failure?

Answer 16

Control HTN, hyperlipidemia, glucose metabolism (diabetes), obesity

Question 17

How does digoxin ultimately increase myocardial contractility?

Answer 17

Increasing the releasable Ca from the SR (more accumulates in SR d/t its MOA)

Question 18

Parasympathomimetic effects of digoxin are inhibited by __

Answer 18

Atropine

Question 19

Where is cholinergic innervation more concentrated in the heart?

Answer 19

The atria

Increased actions of digoxin on atrial and AV nodes comapred to purkinje or ventricular function

Question 20

What is the most common site of digoxin toxicity outside of the heart?

Answer 20

GI –> anorexia, nausea, vomitting, and diarrhea

Question 21

___kalemia can reduce the effects of digoxin (especially the toxic effects

___kalemia can potentiate the toxic effects of digoxin

Answer 21

Hyper

Hypo

Question 22

How are bipyridines administered?

Answer 22

Only available for parenteral

Question 23

These compounds are non-specific PDE inhibitors and their use in HF is limited by their lack of specificity and concomitant side effects

Answer 23

Caffeine and theophylline

Question 24

What toxicity is associated with Milrinone?

Answer 24

Arrhythmias

Question 25

What are the prototypical B-adrenergic and dopaminergic agonists?

Answer 25

Dobutamine (B agonist) | Dopamine (Dopaminergic agonist)

Question 26

What are the MOA of B-adrenergic and dopaminergic agonists?

Answer 26

Act via stimulation of cardiac myocyte dopamine D1 receptor (Dopamine) and B1-adrenergic receptor (Dobutamine)

Question 27

___ is the B agonist of choice for management of pts with systolic dysfunction and HF. It increases stroke volume d/t its positive inotropic action and an increase in CO

Answer 27

Dobutamine

Question 28

At high doses ___ causes peripheral arterial and venous constriction via a-adrenergic receptor stimulation, which may be desirable in pts where circulatory failure is the result of vasodilation (sepsis, anaphylaxis)

Answer 28

Dopamine

Question 29

These diuretics are widely used in the treatment of heart failure

Answer 29

Loops --> furosemide, bumetanide, and torsemide are most commonly used

Question 30

These diuretics are most frequently used in tx of systemic HTN and have a more restricted role in tx of HF

Answer 30

Thiazides

Question 31

What are the prototypical aldosterone antagonists?

Answer 31

Spironolactone and eplerenone

Question 32

This ADH antagonist can tx HF and SIADH and is administered parenterally with a 1/2 life of 5-10 hrs

Answer 32

Conivaptan

Question 33

This ADH antagonist is a selective antagonist of V2 ADH rcepetors that is given PO

Answer 33

Tolvaptan

Question 34

What toxicities are associate with ADH antagonists?

Answer 34

Conivaptan can cause hypernatremia, nephrogenic DI

Question 35

What drug class can be given to potentiate the effects of diuretics in HF?

Answer 35

ACE inhibitors The -pril's

Question 36

What drug class can be given to potentiate the effects of diuretics in HF if a pt is intolerant to a specific drug class that causes a characteristic cough and angioedema?

Answer 36

ARB's The -sartan's Act through AT1 receptors

Question 37

What is the MOA of Isosorbide dinitrate?

Answer 37

Releases NO and activates guanylyl cyclase; is a VENODILATOR Used in acute and chronic HF as well as angina

Question 38

What arteriolar dilator is used in combo with nitrates to reduce mortality in pts w/ HF? What are its toxicities?

Answer 38

Hydralazine Tachycardia, fluid retention, lupus-like syndrome

Question 39

This drug is used for acute cardiac decompensation and hypertensive emergencies (malignant HTN)

Answer 39

Nitroprusside Combined arteriolar and venodilator

Question 40

___ is a recombinant form of human BNP that has been approved for tx of acutely decompensated HF with dyspnea at rest or with minimal activity

Answer 40

Nesiritide

Question 41

What is the MOA of Nesiritide?

Answer 41

Binds to GC receptor on vascular smooth muscle and endothelial cells, increasing intracellular cGMP, resulting in smooth muscle relaxation Given IV

Question 42

___=B1 selective blocker, off-label use for HF in USA ___=Nonselective B blocker and a-1 selective blocker ___=B1 selective blocker, mild-to-moderate HF

Answer 42

Bisprolol Carvedilol Metoprolol

Question 43

What are the prototypical loop diuretics?

Answer 43

Furosemide and ethacrynic acid