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

Losartan (Cozaar) is an angiotensin II receptor blocker (ARB) that is used to treat heart failure by lowering blood pressure and reducing fluid retention.

Patients taking losartan should:

• Weigh themselves every morning and report any changes.

This helps to monitor fluid status and detect signs of worsening heart failure.Weight gain of more than 2 kg (4.4 lb) in a week or 1 kg (2.2 lb) in a day should be reported to the health care provider.

• Call their doctor if they have a sore throat or fever.This could indicate an infection or a rare but serious side effect of losartan called angioedema, which causes swelling of the face, lips, tongue, or throat.

The other choices are wrong because:

• Losartan does not need to be taken with food to prevent stomach upset.It can be taken with or without food.

• Losartan does not increase the sensitivity to sunlight.However, some other medications for heart failure, such as diuretics, may do so.

• Drinking plenty of fluids to stay hydrated is not recommended for patients with heart failure, as it may worsen fluid retention and overload the heart.Patients should follow their prescribed fluid restriction and limit their sodium intake.

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.