Final answer:
The first-line treatment for moderate hypercalcemia is intravenous bisphosphonates, which slow down bone breakdown and maintain bone density. Calcitonin may be used for rapid but short-term effects, and loop diuretics can serve as adjunct therapy for increased calcium excretion.
Step-by-step explanation:
The first-line treatment for moderate hypercalcemia is intravenous bisphosphonates. Bisphosphonates are medications that slow down the breakdown of bone, allowing for bone rebuilding during remodeling, which helps maintain bone density and decreases the risk of fractures. While calcitonin may also be used in the treatment of hypercalcemia, it does so by preventing the movement of Ca2+ from bone and causes phosphate deposition in the bone; its effects on lowering blood calcium levels are milder and act more rapidly than bisphosphonates but are less durable. Loop diuretics can be used as an adjunct therapy to increase calcium excretion in the urine, after volume repletion. Corticosteroids are not the first-line treatment for hypercalcemia, unless the hypercalcemia is due to granulomatous diseases such as sarcoidosis, where they help reduce granuloma formation and vitamin D conversion.