A client with chronic kidney disease (CKD) has an elevated serum phosphorus level. What drug would the nurse anticipate to be prescribed?

Choice A reason: Calcium acetate is a phosphate binder. In clients with CKD, the kidneys cannot excrete phosphorus, leading to hyperphosphatemia. Phosphate binders are taken with meals to bind phosphorus from food in the intestinal tract, forming an insoluble complex that is excreted in the feces, thereby reducing systemic absorption and serum levels. Choice B reason: Doxycycline is a broad-spectrum tetracycline antibiotic. It is used to treat various bacterial infections and has no role in the management of phosphorus or electrolyte imbalances in chronic kidney disease. In fact, some tetracyclines must be used with caution in renal impairment due to potential nephrotoxicity or accumulation. Choice C reason: Lisinopril is an ACE inhibitor used to manage hypertension and provide renal protection by reducing intraglomerular pressure in the early stages of CKD. While it is a common medication for these patients, it does not lower serum phosphorus levels and can actually cause a risk of hyperkalemia in advanced renal failure. Choice D reason: Magnesium sulfate is an electrolyte replacement or anticonvulsant. It is generally avoided or used with extreme caution in CKD patients because the kidneys are responsible for magnesium excretion. Administering it could lead to magnesium toxicity (hypermagnesemia), and it has no clinical utility in the reduction of serum phosphorus.