hypercalcaemia associated with malignancy
Last reviewed 01/2018
Hypercalcaemia is seen in around 20-30% of patients with cancer (1).
It may develop by a combination of increased osteoclastic bone resorption and increased absorption of calcium by the kidney.
- these effects are mediated by parathyroid hormone related protein (PTHrP) which is secreted in excessive amounts by a tumor
- in myeloma, production of PTHrP has been described although osteoclastic activation occurs due to bone-resorbing cytokines such as interleukin-1 (2)
The precise intervention required is dependent upon the level of the hypercalcaemia. In all cases, rehydration is necessary using 3-4 litres of 0.9% saline intravenously over 24 hours and subsequently 2-3 litres/day till a satiafactroy urine output (2 L/day) is established (2).
Frusemide should be given only in the presence or expectation of cardiac failure.
Pamidronate can be added to the hydration fluid. It takes 24-48 hours to take effect with full effect at 4-7 days. In the presence of renal impairment i.e. serum creatinine greater than 400, the pamidronate should be administered in daily divided doses.
Treatment may be repeated at 30 days.
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