A nurse is caring for a client whose serum potassium level is 5.3 mEq/L. Which of the following scheduled medications should the nurse plan to administer?

Choice A rationale Lisinopril is an Angiotensin-Converting Enzyme (ACE) inhibitor used to treat hypertension and heart failure. One of its primary side effects is the retention of potassium by the kidneys through the inhibition of aldosterone. Since the client's potassium level is already elevated at 5.3 mEq/L (normal range is 3.5 to 5.0 mEq/L), administering lisinopril would be contraindicated. The nurse should hold this medication to prevent worsening hyperkalemia, which can lead to life-threatening cardiac arrhythmias and conduction disturbances. Choice B rationale Potassium iodide is a medication used to protect the thyroid gland from radiation or to treat specific thyroid conditions. Because it contains potassium, its administration would further increase the serum potassium level in a client who is already hyperkalemic. The goal of treatment for a potassium level of 5.3 mEq/L is to lower the concentration, not add to it. Therefore, the nurse should not plan to administer potassium iodide, as it would pose a significant risk to the client. Choice C rationale Bumex, or bumetanide, is a potent loop diuretic that inhibits the reabsorption of sodium, chloride, and water in the ascending limb of the loop of Henle. A major side effect of loop diuretics is the increased excretion of potassium in the urine. For a client with hyperkalemia at 5.3 mEq/L, administering a loop diuretic helps lower serum potassium levels by promoting renal elimination. This is an appropriate intervention to bring the potassium level back into the normal range. Choice D rationale Sodium polystyrene sulfonate is a cation-exchange resin specifically indicated for the treatment of hyperkalemia. It works in the gastrointestinal tract by exchanging sodium ions for potassium ions, which are then excreted from the body through the stool. With a potassium level of 5.3 mEq/L, this medication is a standard treatment to reduce the total body potassium load. The nurse must monitor for bowel function, as the medication can cause constipation or more severe intestinal issues.