A patient with atrial fibrillation has been prescribed digoxin (Lanoxin). The nurse should monitor which laboratory value to evaluate therapeutic effectiveness?

This is because diltiazem (Cardizem) is a calcium channel blocker that lowers blood pressure and can cause orthostatic hypotension, which is a sudden drop in blood pressure when standing up from a sitting or lying position. This can lead to dizziness and lightheadedness, which can increase the risk of falls and injuries. Changing positions slowly can help prevent or reduce these symptoms by allowing the body to adjust to the change in blood pressure.

Choice A) Administer diltiazem as ordered by physician is wrong because it does not address the patient’s complaint of dizziness and lightheadedness, which are side effects of the medication.

The nurse should monitor the patient’s blood pressure and heart rate before and after administering diltiazem, and report any abnormal findings to the physician.

Choice C) Notify physician immediately is wrong because it is not necessary to notify the physician immediately for a common and mild side effect of diltiazem, unless the patient has other signs of severe hypotension, such as fainting, chest pain, or confusion.

The nurse should educate the patient about the possible side effects of diltiazem and how to prevent or manage them.

Choice D) Hold diltiazem and notify physician if symptoms persist is wrong because it is not appropriate to hold a prescribed medication without a valid reason or an order from the physician.

Holding diltiazem could cause the patient’s blood pressure to rise and increase the risk of complications from atrial fibrillation, such as stroke or heart failure.

The nurse should administer diltiazem as ordered and monitor the patient’s response.

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.