From the Guidelines

Hypercalcemia treatment typically involves a combination of hydration, bisphosphonates, and other medications.

Hydration: Parenteral hydration with normal saline is recommended to correct hypercalcemia-associated hypovolaemia and promote calciuresis 1.
Bisphosphonates: Bisphosphonates, such as i.v. pamidronate and zoledronic acid, may control hypercalcemia and reverse delirium in a substantial number of cases 1. The recommended dose of zoledronic acid is 4 mg for the initial treatment of hypercalcemia, with the 8-mg dose reserved for relapsed or refractory cases 1.
Denosumab: Denosumab, a human monoclonal antibody and RANKL inhibitor, is a potent inhibitor of bone resorption used in the management of bone metastases and hypercalcemia, particularly in patients refractory to bisphosphonate treatment 1.
Calcitonin: Calcitonin may be used in addition to bisphosphonates and hydration to reduce calcium levels 1.
Steroids: Steroids may be used in the treatment of hypercalcemia, although their use is not as well established as bisphosphonates and hydration 1.

Monitoring: Serum calcium levels should be monitored closely during treatment, particularly in patients receiving denosumab, as they are at increased risk of developing hypocalcaemia 1.
Dose adjustment: Dose reduction should be considered for patients with renal failure who require bisphosphonates for bone disease 1.
Contraindications: Bisphosphonates should be discontinued in patients with unexplained albuminuria or increased serum creatinine 1.

From the Research

The treatment of hypercalcemia is based on treating the underlying disease, restoring extracellular volume, correcting electrolyte deficiencies, and reducing bone resorption 2.
Several measures are available to reduce bone resorption, including bisphosphonates and plicamycin (mithramycin) 2.
Calcitonin has a more modest hypocalcemic action than bisphosphonates or plicamycin but has a more rapid effect 2.
Combining calcitonin with plicamycin or a bisphosphonate can enhance the rate of decline of the serum calcium level 2.

Bisphosphonates, such as zoledronic acid or pamidronate, are considered the drugs of choice for the long-term management of hypercalcemia 3, 4.
Calcitonin is preferable for the short-term control of severe hypercalcemia 4.
Glucocorticoids may be effective in patients with hypercalcemia associated with high levels of vitamin D, such as sarcoidosis, some lymphomas, or vitamin D intoxication 2, 5.
Denosumab may be used in patients with kidney failure or those who do not respond to bisphosphonates 3, 4.

Mild hypercalcemia usually does not require acute intervention, but treatment should be directed at the primary disease and preventing complications 2, 3.
Initial therapy for symptomatic or severe hypercalcemia consists of hydration and intravenous bisphosphonates 3, 5.
The underlying cause of hypercalcemia should be identified and treated 3, 5.
Patients with hypercalcemia of malignancy may require more aggressive treatment, including bisphosphonates, calcitonin, and glucocorticoids 3, 6.