What is the treatment for severe hypercalcemia?

From the Guidelines

The patient should be treated with aggressive intravenous fluid rehydration using normal saline at rates of 200-300 mL/hour, followed by loop diuretics like furosemide (20-40 mg IV) once adequately hydrated, and bisphosphonates, preferably zoledronic acid (4 mg IV over 15-30 minutes), as the mainstay of treatment for severe hypercalcemia, as recommended by the most recent guidelines 1. The treatment approach for severe hypercalcemia involves a multi-step process to rapidly lower serum calcium levels and prevent life-threatening complications.

• Aggressive intravenous fluid rehydration is crucial to increase renal calcium excretion and correct dehydration.
• Loop diuretics, such as furosemide, should be administered once the patient is adequately hydrated to further enhance renal calcium excretion.
• Bisphosphonates, with zoledronic acid being the preferred option 1, are the mainstay of treatment, as they inhibit bone resorption and effectively lower serum calcium levels.
• Additional treatments, such as calcitonin (4-8 IU/kg SC/IM every 12 hours), can provide rapid but short-term calcium reduction while waiting for bisphosphonates to take effect.
• Denosumab (120 mg SC) may be considered as an alternative for patients with renal impairment, and cinacalcet (30-90 mg orally daily) can be useful for hypercalcemia due to hyperparathyroidism. The underlying cause of hypercalcemia must be identified and treated simultaneously to prevent recurrence and improve patient outcomes, as emphasized in the guidelines 1.

From the FDA Drug Label

The maximum recommended dose of zoledronic acid injection in hypercalcemia of malignancy (albumin-corrected serum calcium greater than or equal to 12 mg/dL [3. 0 mmol/L]) is 4 mg. The 4 mg dose must be given as a single-dose intravenous infusion over no less than 15 minutes. Patients who receive zoledronic acid injection should have serum creatinine assessed prior to each treatment Vigorous saline hydration, an integral part of hypercalcemia therapy, should be initiated promptly and an attempt should be made to restore the urine output to about 2 L/day throughout treatment.

The patient has a calcium level of 13.8, which is above the threshold for hypercalcemia of malignancy.

• Initial Treatment: The patient should be given vigorous saline hydration to restore urine output and correct hypovolemia.
• Zoledronic Acid: The patient may be considered for zoledronic acid injection 4 mg as a single-dose intravenous infusion over no less than 15 minutes, after assessing serum creatinine and ensuring adequate rehydration.
• Monitoring: Serum creatinine and calcium levels should be carefully monitored throughout treatment.
• Loop Diuretics: Loop diuretics may be used with caution after the patient is adequately rehydrated, to avoid hypocalcemia. 2

From the Research

Treatment for Severe Hypercalcemia

The patient's calcium level is 13.8, which is considered severe hypercalcemia. According to the studies, the initial therapy for symptomatic or severe hypercalcemia consists of:

• Hydration
• Intravenous bisphosphonates, such as zoledronic acid or pamidronate 3, 4

Intervention

The following interventions can be considered:

• Normal saline hydration to decrease calcium levels 4
• Intravenous zoledronic acid, which has been shown to be effective in reducing serum calcium levels 4, 5, 6
• Monitoring of serum calcium levels and renal function, as intravenous bisphosphonates can cause renal dysfunction 7

Considerations

• The underlying cause of hypercalcemia should be identified and treated 3
• Glucocorticoids may be used as primary treatment when hypercalcemia is due to excessive intestinal calcium absorption (vitamin D intoxication, granulomatous disorders, some lymphomas) 3
• Patients with kidney failure may require denosumab and dialysis 3