21st June 2023

Management

Treatment depends on the severity of the hypercalcaemia and the patient’s symptomatology.

• Mild hypercalcaemia: <3.00mmol/L
• Moderate hypercalcaemia: 3-3.50mmol/L
• Severe hypercalcaemia: >3.50mmol/L or symptomatic

Treatment for malignant hypercalcaemia should firstly include conservative measures, targeting potential contributing factors, such as avoiding thiazide diuretics, calcium supplementation and dehydration. Initially, patients should be managed with intravenous fluid resuscitation as concurrent hypovolaemia is common and correcting this will promote renal excretion. Typically 2L of fluid is required every 24 hours for 48-72 hours. Following this, if renal function is permissive, zoledronic acid 4 mg IV should be administered, re-checking the calcium after 4-7 days. If GFR is 30-50 ml/min, administer a reduced dose of 3 mg.

If malignant hypercalcaemia is recurrent, especially in the context of malignancy with extensive bony metastases, denosumab may be administered prophylactically. This has the additional benefit of aiding with bony pain. It is important that prior to its administration, serum vitamin D levels are checked. Supplementation with calcium and vitamin D should be co-administered if denosumab is to be continued. Denosumab is licensed for the treatment of bony pain in all solid tumours with bony metastases except prostate cancer, where zoledronic acid should be employed.