cardiac glycosides

Question 1

How do Cardiac Glycosides work?

Answer 1

Inhibit the sodium-potassium pump, increasing calcium in the cells, which helps the heart muscle contract better.

Question 2

What are the effects of Cardiac Glycosides?

Answer 2

Positive inotropes (increased contractility) leading to stronger contractions and increased cardiac output, which enhances renal perfusion and reduces edema and fluid overload. They also act as negative chronotropes (decrease HR).

Question 3

When are cardiac glycosides used?

Answer 3

Used to treat heart failure (HF) when patients are not improving with other treatments.

Question 4

What is Heart Failure?

Answer 4

Occurs when the heart muscle has weakened and enlarged, reducing its ability to pump blood effectively, leading to decreased cardiac output.

Question 5

What are the two types of Heart Failure?

Answer 5

Systolic - the heart isn’t pumping strong enough (ejection fraction < 50%). Diastolic - the heart isn’t relaxing enough (ejection fraction normal: 50-75%).

Question 6

What is Congestive Heart Failure (CHF)?

Answer 6

Occurs when compensatory mechanisms fail, leading to congestion and fluid overload in peripheral tissues and lungs.

Question 7

What are the signs of Left-sided CHF?

Answer 7

Pulmonary congestion, shortness of breath (SOB), cough, weight gain, oliguria.

Question 8

What are the signs of Right-sided CHF?

Answer 8

Peripheral edema, jugular venous distension (JVD), weight gain.

Question 9

What are the causes of Heart Failure?

Answer 9

Chronic hypertension, myocardial infarction (MI), coronary artery disease (CAD), valvular disease, congenital heart disease, aging.

Question 10

What is Lanoxin (Digoxin) used for?

Answer 10

Used as a second/third line treatment for HF and for patients with low BP who can’t tolerate beta-blockers or calcium channel blockers, mainly for its negative chronotropic effect in atrial fibrillation/tachycardia.

Question 11

What pregnancy category is Lanoxin (Digoxin)?

Answer 11

Pregnancy category C.

Question 12

How is Lanoxin (Digoxin) administered?

Answer 12

Given orally (PO) or intravenously (IV). Therapeutic window is 0.5-2.0. Half-life is 30-40 hours. Loading dose: 3 doses every 6 hours until therapeutic level is reached, then once daily.

Question 13

How is Lanoxin (Digoxin) metabolized and excreted?

Answer 13

50-70% excreted by kidneys, 30% metabolized by liver.

Question 14

In which patients should the dose of Digoxin be lowered?

Answer 14

Hypothyroid patients and patients with renal insufficiency, monitoring their creatinine levels.

Question 15

What are the signs of Digoxin toxicity?

Answer 15

Bradycardia, anorexia, nausea/vomiting/diarrhea, visual changes (specifically yellow halos), confusion, delirium, dysrhythmias (ventricular).

Question 16

What is the antidote for Digoxin toxicity?

Answer 16

DIGIBIND, OVINE.

Question 17

What are the drug interactions of Digoxin?

Answer 17

Potassium-wasting diuretics (increase toxicity), cortisone solution (increases hypokalemia), antacids (decrease absorption).

Question 18

What are nursing considerations for Digoxin?

Answer 18

Obtain apical pulse before administration, assess for signs of toxicity, monitor potassium and digoxin levels.

Question 19

What do Phosphodiesterase inhibitors do?

Answer 19

Improve cardiac output.

Question 20

What are the six Phosphodiesterase inhibitors?

Answer 20

Primacor (milrinone), Inocor, vasodilators, arteriolar dilators, ACE inhibitors, diuretics (aldactone/spironolactone), beta-blockers (natrecor).

Question 21

When are Primacor (milrinone) and Inocor used?

Answer 21

Given IV only for 48-72 hours for patients with decompensated HF (fluid overload).

Question 22

What effects do Primacor (milrinone) and Inocor have?

Answer 22

Positive inotropes that increase stroke volume, cardiac output, vasodilation, and tissue perfusion, helping to eliminate excess fluid. Cardioselective; may cause cardiac dysrhythmias - monitor EKGs.

Question 23

How do vasodilators work?

Answer 23

Decrease blood return to the heart, improving contractility.

Question 24

How do arteriolar dilators work?

Answer 24

Decrease afterload, which increases cardiac output, renal perfusion, and circulation to the muscles.

Question 25

How do ACE inhibitors work?

Answer 25

Dilate venules and arterioles, improve renal blood flow, reduce blood pressure, and decrease blood fluid volume.

Question 26

How do diuretics (Aldactone/Spironolactone) work?

Answer 26

Potassium-sparing diuretics that block the secretion of aldosterone, lowering fluid retention and decreasing morbidity/mortality rates of HF.

Question 27

To whom are beta-blockers (Natrecor) given and how?

Answer 27

Given IV to patients with CHF (fluid overloaded and have HF).

Question 28

How do beta-blockers (Natrecor) work?

Answer 28

Inhibit ADH, causing diuresis in acute CHF and promoting vasodilation.

Question 29

What is the combo drug for HF?

Answer 29

BiDil, a combination of hydralazine and isosorbide dinitrate, helps with vasodilation.