Non‐Parathyroid Hypercalcemia

This chapter provides practical guidance on the diagnosis, treatment and management of non-parathyroid hypercalcemia. Hypercalcemia raises the electrical potential difference across cell membranes, and increases the depolarization threshold. Clinically, this is manifest as a spectrum of neurological symptoms ranging from mild tiredness, to obtundation, to coma. The chapter also considers nonparathyroid causes of hypercalcemia. In patients whose hypercalcemia is primarily based on accelerated bone resorption, therapy should include agents that block bone resorption, such as zoledronate, pamidronate, or denosumab. For patients with cancer, the most effective long-term therapy is tumor eradication. If this is not possible, or while waiting for a response to chemotherapy, aggressive hydration with saline, keeping a careful watch for signs of congestive heart failure, accompanied by a loop diuretic such as furosemide, are appropriate. For immobilization-induced hypercalcemia, weight bearing ambulation is the mainstay of therapy.