A patient has 2+ pitting edema of the lower extremities bilaterally. Auscultation of the lungs reveals crackles bilaterally, and the serum potassium level is 6 mEq/L, which is above normal level. Which agent ordered by the prescriber should the nurse question?

Choice A reason: This is not the agent that the nurse should question. Beta blockers are a class of medications that lower the blood pressure and heart rate by blocking the beta receptors in the heart and blood vessels. They can be used to treat hypertension, angina, heart failure, and arrhythmias. They do not cause edema or hyperkalemia.

Choice B reason: This is not the agent that the nurse should question. Alpha 2 agonists are a class of medications that lower the blood pressure by stimulating the alpha 2 receptors in the brain, which reduce the sympathetic nervous system activity. They can be used to treat hypertension, especially in patients with renal impairment. They do not cause edema or hyperkalemia.

Choice C reason: This is not the agent that the nurse should question. Calcium channel blockers are a class of medications that lower the blood pressure and heart rate by blocking the calcium channels in the heart and blood vessels, which cause vasodilation and reduced cardiac contractility. They can be used to treat hypertension, angina, and arrhythmias. They may cause edema, but not hyperkalemia.

Choice D reason: This is the agent that the nurse should question. Aldosterone antagonists are a class of medications that lower the blood pressure and reduce fluid retention by blocking the action of aldosterone, a hormone that regulates the sodium and potassium balance in the body. They can be used to treat hypertension and heart failure, especially in patients with low renin levels. However, they can cause hyperkalemia, which can be dangerous for the patient. The nurse should question the prescriber about the rationale for prescribing this agent and monitor the patient's potassium level closely.