Hypercalcemia of malignancy: diagnosis and therapy.

Therapy should be individualized on the basis of patient symptoms, severity of hypercalcemia, and prospects for inducing a remission in the underlying malignancy. We have found the most effective approach to be vigorous hydration of the patient, usually intravenously with normal saline at a rate of 300 to 500 mL/h. Intravenous furosemide is given as needed to prevent fluid overload. If the patient is volume replete and if hypercalcemia persists after 24 to 48 hours of intravenous hydration, calcitonin, 200 MRC units subcutaneously every 12 hours plus prednisone, 20 mg orally four times daily, are added. In most cases, a response is seen shortly after institution of this therapy. Meanwhile, attempts to treat the malignancy are initiated, including palliative radiation therapy for bony metastases. If the patient is still hypercalcemic and symptomatic after seven days of this therapy, treatment with plicamycin is given unless the patient's condition is clearly terminal. At present, use of prostaglandin synthetase inhibitors is not recommended, and bisphosphonates are available only for investigational use.