A nurse is caring for a client who is taking tamoxifen to treat breast cancer. The nurse should identify which of the following manifestations as an adverse effect of this medication?

Taking a high-ceiling diuretic predisposes this client to developing digoxin toxicity because it can cause hypokalemia (low blood potassium level), which increases the sensitivity of the heart to digoxin. Digoxin is a medicine that is used to treat heart failure or arrhythmias (abnormal heart rhythms) by increasing cardiac contractility and controlling the heart rate. Digoxin toxicity happens when there is too much digoxin in the body and it becomes harmful, causing symptoms such as nausea, vomiting, headache, confusion, vision disturbance, and irregular heartbeat.

Choice A is wrong because taking an HMG CoA reductase inhibitor (also called a statin) does not increase the risk of digoxin toxicity.

Statins are lipid-lowering medications used to prevent coronary heart disease by blocking an enzyme involved in cholesterol synthesis.

Statins do not affect the blood potassium level or the sensitivity of the heart to digoxin.

Choice B is wrong because having a 10-year history of COPD (chronic obstructive pulmonary disease) does not increase the risk of digoxin toxicity. COPD is a lung condition that causes breathing difficulties and chronic inflammation.

COPD does not affect the blood potassium level or the sensitivity of the heart to digoxin.

Choice D is wrong because having a prolapsed mitral valve does not increase the risk of digoxin toxicity.

A prolapsed mitral valve is a condition where the valve between the left atrium and left ventricle of the heart does not close properly, allowing some blood to leak back into the atrium.

A prolapsed mitral valve does not affect the blood potassium level or the sensitivity of the heart to digoxin.

This is a high level of potassium in the blood (the normal range is 3.5 to 5 mEq/L) and can be dangerous for the heart.

Triamterene is a potassium-sparing diuretic that prevents the body from losing too much potassium in the urine. It can cause hyperkalemia (high potassium), especially in people with kidney disease, diabetes, or severe illness. The nurse should check the potassium level before giving triamterene and hold the medication if it is above 5 mEq/L.

The other choices are incorrect because:

Choice A: Sodium 142 mEq/L.

This is a normal level of sodium in the blood (the normal range is 135 to 145 mEq/L) and does not require withholding triamterene. Triamterene can cause hyponatremia (low sodium) by increasing the excretion of sodium in the urine. The nurse should monitor the sodium level during triamterene therapy and report any signs of low sodium such as confusion, weakness, or seizures.

Choice B: BUN 16 mg/dL.

This is a normal level of blood urea nitrogen (BUN) in the blood (normal range is 7 to 20 mg/dL) and does not require withholding

triamterene. BUN is a measure of kidney function and can be elevated in kidney disease or dehydration. Triamterene can cause an increase in BUN by reducing the blood flow to the kidneys or by interacting with other medications that affect the kidneys. The nurse should monitor the BUN level during triamterene therapy and report any signs of kidney impairment such as decreased urine output, swelling, or nausea. •

Choice D: Albumin 4 g/dL.

This is a normal level of albumin in the blood (the normal range is 3.4 to 5.4 g/dL) and does not require withholding triamterene. Albumin is a protein that helps maintain fluid balance and transport substances in the blood. Triamterene does not affect albumin levels directly, but it can cause fluid loss or retention that may alter albumin levels indirectly. The nurse should monitor the albumin level during triamterene therapy and report any signs of fluid imbalance such as weight changes, edema, or shortness of breath.