Which drug blocks the binding of angiotensin II to its receptors on blood vessels and adrenal glands, preventing its vasoconstrictive and aldosterone-stimulating effects?

The nurse should monitor the serum potassium level to determine the therapeutic effectiveness of digoxin (Lanoxin), a cardiac glycoside that improves the contractility and pumping ability of the heart. Digoxin has a narrow therapeutic range and can cause toxicity if the serum level is too high or if the patient has hypokalemia (low potassium).Hypokalemia can result from diuretic therapy, which is often prescribed for heart failure patients to reduce fluid overload.

Therefore, the nurse should monitor the serum potassium level and report any abnormal values to the provider.The normal potassium level is 3.5 to 5.0 mEq/L.

Choice B) Serum sodium level is wrong because sodium level is not directly affected by digoxin therapy.

Sodium level may be altered in heart failure patients due to fluid retention or diuretic use, but it does not indicate the effectiveness of digoxin.

Choice C) Serum magnesium level is wrong because magnesium level is not directly affected by digoxin therapy.

Magnesium level may be altered in heart failure patients due to diuretic use or renal impairment, but it does not indicate the effectiveness of digoxin.

Choice D) Serum calcium level is wrong because calcium level is not directly affected by digoxin therapy.

Calcium level may be altered in heart failure patients due to renal impairment or vitamin D deficiency, but it does not indicate the effectiveness of digoxin.

Digoxin (Lanoxin) is a cardiac glycoside that is used to improve the contractility of the heart and slow down the heart rate in patients with chronic heart failure. However, digoxin has a narrow therapeutic range and can cause toxicity if the dose is too high or if the patient has low potassium levels. A normal serum digoxin level is 0.5 to 2 ng/mL and a normal serum potassium level is 3.5 to 5 mEq/L. A low heart rate (less than 60 beats/min) is a sign of digoxin toxicity and the nurse should withhold the medication and report it to the provider. The nurse should also check the patient’s serum digoxin and potassium levels to determine if they are within normal limits.

Choice A is wrong because administering the medication as ordered could worsen the patient’s condition and increase the risk of digoxin toxicity.

Choice C is wrong because checking the patient’s serum digoxin level is not enough to prevent digoxin toxicity. The nurse should also check the patient’s serum potassium level and heart rate before giving digoxin.

Choice D is wrong because giving an additional dose of digoxin could cause a fatal overdose and lead to cardiac arrest. The nurse should never give more than the prescribed dose of digoxin without consulting the provider.