A nurse is providing teaching to a client who has stable angina and a new prescription for nitroglycerin oral, sustained-release capsules. Which of the following instructions should the nurse include?

Hypokalemia is a low serum potassium level, usually below 3.5 mEq/L. It can be caused by diuretics that increase potassium excretion, such as thiazides or loop diuretics. Potassium is essential for normal muscle and nerve function, and hypokalemia can impair cardiac, skeletal, and smooth muscle activity. Symptoms of hypokalemia include fatigue, weakness, muscle cramps, arrhythmias, constipation, and hyporeflexia.

1. Dyspnea is difficulty or labored breathing that can be caused by various respiratory or cardiac conditions, such as asthma, pneumonia, pulmonary edema, or heart failure. It is not a specific sign of hypokalemia, although severe hypokalemia can affect respiratory muscle function and cause respiratory failure.
2. Oliguria is a reduced urine output, usually less than 400 mL per day or 30 mL per hour. It can be caused by various renal or fluid balance disorders, such as acute kidney injury, dehydration, or shock. It is not a specific sign of hypokalemia, although severe hypokalemia can impair renal function and cause renal failure.
3. Pitting edema is a swelling of the tissues that leaves an indentation when pressed with a finger. It can be caused by various fluid retention disorders, such as heart failure, liver cirrhosis, or nephrotic syndrome. It is not a specific sign of hypokalemia, although severe hypokalemia can affect fluid and electrolyte balance and cause edema.

The nurse should check the client's vital signs first because nausea and weakness are signs of digoxin toxicity, which can also cause bradycardia, hypotension, and arrhythmias. The nurse should also assess the client's serum digoxin level, potassium level, and electrocardiogram.

Request a dietitian consult is wrong because it is not the priority action and it does not address the possible cause of the client's symptoms. A dietitian consult may be helpful to provide nutritional education and guidance, but only after ruling out or treating digoxin toxicity.

Suggest that the client rests before eating the meal is wrong because it is not the priority action and it may delay the diagnosis and treatment of digoxin toxicity. The nurse should not assume that the client's symptoms are due to fatigue or lack of appetite, but rather investigate for any underlying problems.

Request an order for an antiemetic is wrong because it is not the priority action and it may mask the symptoms of digoxin toxicity. The nurse should not administer any medications that could interact with digoxin or worsen its effects, but rather notify the provider and follow the protocol for digoxin toxicity management.