A nurse is caring for a client with an elevated serum potassium level of 6.0 mEq/L (3.5-5.0 mEq/L). Which scheduled medication should the nurse plan to administer?

The correct answer is D: Sodium polystyrene sulfonate. This medication is a potassium-lowering agent used to treat hyperkalemia. It works by exchanging sodium ions for potassium ions in the intestines, leading to the elimination of excess potassium from the body. Sertraline (A) is an antidepressant, Captopril (B) is an ACE inhibitor used for hypertension, and Digoxin (C) is a cardiac glycoside used for heart failure and atrial fibrillation. None of these medications are indicated for treating hyperkalemia. Therefore, the nurse should plan to administer Sodium polystyrene sulfonate to address the elevated potassium level in the client's serum.