Introduction:
Denosumab requires no dose adjustment in renal failure but the risk of precipitating hypocalcaemia in patients with an eGFR <30ml/min remains high.¹

Case 1:
An 80 year old female presented following a minimal trauma fracture with the background of fragility fractures and stage IV chronic kidney disease (CKD) secondary to hypertensive nephrosclerosis. Her regular medications included cholecalciferol and calcium carbonate. Asymptomatic hypocalcaemia ensued which was managed with calcitriol and calcium carbonate. She recovered uneventfully.

Case 2:
An 81 year old female presented with vertebral crush fractures on the background of stage IV CKD of unknown aetiology and chronic myelomonocytic leukaemia. She commenced cholecalciferol and calcium carbonate prior to denosumab therapy. She developed asymptomatic hypocalcaemia and was managed with calcitriol and intravenous calcium gluconate. Her serum calcium improved but she succumbed to pneumonia.

Conclusion:
Denosumab provides a 20% relative risk reduction of fractures in women with osteoporosis regardless of kidney function.^2,3 It is uncertain how aggressive secondary hyperparathyroidism should be managed and whether this mitigates the risk of hypocalcaemia. We reviewed the literature for similar cases and discuss the limitations of current evidence. We propose caution with the use of denosumab in patients with stage IV CKD.