Hyperphosphatemia

Key Features

• Advanced CKD is the most common cause

• Hyperphosphatemia in the presence of hypercalcemia imposes a high risk of metastatic calcification

• Main cause is advanced chronic kidney disease (CKD) with insufficient urinary excretion of phosphorus

• Hyperphosphatemia in the presence of hypercalcemia imposes a high risk of metastatic calcification

Clinical Findings

• Symptoms are those of the underlying disorders (eg, CKD, hypoparathyroidism)

Diagnosis

• Elevated phosphate levels

• Blood chemistry abnormalities are those of the underlying disease

Treatment

• Treatment is directed at the underlying disorder

• Exogenous sources of phosphate, including enteral or parenteral nutrition and medications, should be reduced or eliminated

• In acute kidney injury and CKD, dialysis will reduce serum phosphate

• Dietary phosphate absorption can be reduced by oral phosphate binders, such as

  • Calcium carbonate

  • Calcium acetate

  • Sevelamer carbonate

  • Lanthanum carbonate

  • Aluminum hydroxide

• Sevelamer, lanthanum, and aluminum may be used in patients with concomitant hypercalcemia, although aluminum use should be limited to a few days because of the risk of aluminum accumulation and neurotoxicity