Omori Makiko, Matsukawa Yukihiro, Ikeda Yuhachi, Sakai Tomoyuki
Pediatrics, Shiga University of Medical Science, Otsu, Shiga, Japan.
Pediatrics, Shiga University of Medical Science, Otsu, Shiga, Japan
BMJ Case Rep. 2025 Jan 8;18(1):e263129. doi: 10.1136/bcr-2024-263129.
Denosumab, an anti-RANKL antibody, induces bone metabolism to a low-turnover bone status by arresting osteoclast activity. Frequent adverse events include infusion reactions, fever and hypocalcaemia but not hypophosphataemia. We report a case of severe hypophosphataemia associated with secondary hyperparathyroidism following denosumab administration in a young boy with recurrent osteosarcoma who was successfully treated with evocalcet. He developed hypocalcaemia and severe refractory hypophosphataemia after receiving denosumab for bone metastases despite calcium, cholecalciferol and phosphorus supplementation. Laboratory data revealed secondary hyperparathyroidism due to denosumab-induced hypocalcaemia as the cause of hypophosphataemia. Evocalcet contributed to the normalised parathyroid hormone and phosphorus levels, allowing the discontinuation of phosphorus supplementation. This case highlights the complexity of managing electrolyte imbalances induced by bone-modifying agents, such as denosumab, underscoring the importance of monitoring bone metabolism markers and the potential effectiveness of evocalcet in managing drug-induced secondary hyperparathyroidism and hypophosphataemia.
地诺单抗是一种抗核因子κB受体活化因子配体（RANKL）抗体，通过抑制破骨细胞活性诱导骨代谢进入低转换骨状态。常见的不良事件包括输液反应、发热和低钙血症，但不包括低磷血症。我们报告了一例在一名患有复发性骨肉瘤的小男孩中，地诺单抗给药后出现与继发性甲状旁腺功能亢进相关的严重低磷血症的病例，该患儿通过使用依维卡塞成功治疗。尽管补充了钙、胆钙化醇和磷，但他在接受地诺单抗治疗骨转移后仍出现了低钙血症和严重的难治性低磷血症。实验室数据显示，地诺单抗诱导的低钙血症导致继发性甲状旁腺功能亢进，这是低磷血症的原因。依维卡塞使甲状旁腺激素和磷水平恢复正常，从而可以停止补充磷。该病例凸显了管理由地诺单抗等骨修饰剂引起的电解质失衡的复杂性，强调了监测骨代谢标志物的重要性以及依维卡塞在管理药物诱导的继发性甲状旁腺功能亢进和低磷血症方面的潜在有效性。
