Individuals at risk of developing hypercalcemia may be the first to recognize symptoms such as fatigue. Patients should be advised about the ways in which hypercalcemia most frequently manifests itself and should also be given guidelines for seeking professional intervention. Preventive measures include ensuring adequate fluid intake of 3 to 4 L (100–140 fl oz per day if not contraindicated) and salt intake, nausea and vomiting control, encouraging patient mobility, attention to febrile episodes, and cautious use or elimination of drugs that may complicate management. This includes drugs that inhibit urinary calcium excretion or decrease renal blood flow, as well as medications that contain calcium, vitamin D, vitamin A, or other retinoids.
Even though the gut has a role in normal calcium homeostasis, absorption is usually diminished in individuals with hypercalcemia, making dietary calcium restriction unnecessary.
Symptomatic treatment of hypercalcemia focuses first on correcting dehydration and enhancing renal calcium excretion, followed by specific hypocalcemic treatment with agents that inhibit bone resorption (e.g., calcitonin, bisphosphonates, gallium nitrate, and plicamycin).[2,3] Definitive treatment is that which effectively treats the malignant disease underlying hypercalcemia. At one time, hypercalcemia was treated with aggressive intravenous hydration using isotonic saline followed by the administration of a diuretic. This volume expansion and natriuresis was performed to increase renal blood flow and enhance calcium excretion. This approach is not very effective in correcting hypercalcemia and can lead to complications of fluid overload. Intravenous fluid should be administered to correct water loss associated with calciuresis and dehydration due to vomiting. Administration of diuretics should be restricted to balancing urine output in patients who have been adequately rehydrated.
The magnitude of hypercalcemia and the severity of symptoms typically form the basis for determining whether treatment is indicated. Immediate aggressive hypocalcemic treatment is warranted in patients with a corrected total serum calcium level higher than 14 mg/dL (>7 mEq/L or 3.5 mmol/L). In patients with a total corrected serum calcium concentration between 12 and 14 mg/dL (6–7 mEq/L or 3.0–3.5 mmol/L), clinical manifestations should guide the type of therapy and the urgency with which it is implemented. Treatment response is indicated by resolution of symptoms attributable to hypercalcemia and by diminishing serum calcium concentrations and urinary calcium and hydroxyproline excretion.