Severe symptomatic hypocalcaemia following a single dose of denosumab
To the Editor: Denosumab, a receptor activator of nuclear factor κ-B (RANK) ligand inhibitor, is now considered first-line therapy to prevent skeletal-related events in patients with bone metastases secondary to breast cancer and castration-resistant prostate cancer.1,2
We describe a case of severe symptomatic hypocalcaemia in a 91-year-old woman with symptomatic bone-dominant metastatic breast cancer after being treated with denosumab. She had the predisposing factor of a low baseline 25-hydroxyvitamin D level, and was treated with cholecalciferol (3000 IU daily) and calcium supplementation (600 mg twice daily) at the time of initiation of denosumab therapy. Her renal function was normal.
The patient’s general practitioner administered a single subcutaneous dose of denosumab (120 mg) with the intention of delivering monthly doses on an ongoing basis. The patient’s calcium level was monitored regularly,…