Digoxin (Lanoxin) is a cardiac glycoside that is among the oldest medications used for heart failure.
What are its two primary actions?

Diuretics are drugs that increase the amount of urine and salt (sodium) excreted by the kidneys. They are used to treat high blood pressure, heart failure, and edema (fluid retention). However, some diuretics can cause low levels of potassium in the blood (hypokalemia), which can lead to muscle weakness, cramps, and arrhythmias. To prevent this, a combination of diuretics acting on different parts of the kidney (such as a loop diuretic and a thiazide diuretic) may be prescribed.This way, the potassium-sparing effect of one diuretic can balance the potassium-wasting effect of the other, while still achieving a net sodium loss.

Choice A is wrong because they are not a part of the initial diuretic therapy.Combination diuretic therapy is usually reserved for patients who are resistant to or intolerant of monotherapy.

Choice C is wrong because little follow up is not needed after the initial treatment.Patients on combination diuretic therapy require close monitoring of their blood pressure, electrolytes, renal function, and weight to avoid adverse effects such as dehydration, hyponatremia, hypotension, and worsening renal function.

Choice D is wrong because they do not increase the risk of hypokalemia.As explained above, combination diuretic therapy aims to reduce the risk of hypokalemia by using a potassium-sparing diuretic along with a potassium-wasting diuretic.

Normal ranges for serum potassium are 3.5 to 5.0 mmol/L and for serum sodium are 135 to 145 mmol/L.

Digibind is the trade name forantidigoxin, which is an antibody made up of anti-digoxin immunoglobulin fragments.It is thespecific antidoteto digoxin toxicity, which can occur even when the serum digoxin concentration is within the therapeutic range.Digoxin toxicity causes anorexia, nausea, vomiting, neurological symptoms and arrhythmias.

Choice A, Protamine sulfate, is wrong because it is the antidote for heparin overdose, not digoxin toxicity.

Protamine sulfate reverses the anticoagulant effect of heparin by binding to it and forming a stable complex.

Choice B, Acetylcysteine, is wrong because it is the antidote for acetaminophen overdose, not digoxin toxicity.

Acetylcysteine replenishes glutathione, which is depleted by acetaminophen metabolites that cause hepatotoxicity.

Choice D, Vitamin K, is wrong because it is the antidote for warfarin overdose, not digoxin toxicity.

Vitamin K restores the synthesis of clotting factors that are inhibited by warfarin.

Normal ranges for serum digoxin concentration are 0.6 to 1.2 nanomol/L (0.5 to 0.9 nanograms/mL) for heart failure and unknown for atrial fibrillation without heart failure.

Normal ranges for serum potassium level are 3.5 to 5.0 mmol/L and for serum magnesium level are 0.7 to 1.0 mmol/L.