PhosLo (calcium acetate) is used to treat which condition in patients with renal failure?

• A. Hypophosphatemia
• B. Hypokalemia
• C. Hyperphosphatemia
• D. Hyponatremia

Answer: (C)

In renal failure the kidneys can’t excrete phosphate effectively, so phosphate builds up in the blood (hyperphosphatemia). Calcium acetate acts as a phosphate binder in the gastrointestinal tract. When taken with meals, it binds dietary phosphate to form insoluble calcium phosphate, which is then excreted in the stool. This lowers serum phosphate levels and helps prevent complications like secondary hyperparathyroidism and bone disease that accompany CKD.

Be aware that adding calcium increases the risk of hypercalcemia, so monitoring calcium and the calcium-phosphate product is important, especially if vitamin D is also used. The other electrolyte problems listed are not the target of this medication.