Secondary Hyperparathyroidism — RACP Adult Medicine MCQ

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ModerateNephrologySecondary HyperparathyroidismRACP Adult Medicine

A 55-year-old man with chronic kidney disease and secondary hyperparathyroidism has a PTH of 450 pg/mL (target 2–9× ULN), calcium 2.35 mmol/L, and phosphate 1.8 mmol/L. He is already on a phosphate binder and vitamin D analogue (calcitriol). What additional medication should be considered?

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Correct answer: C — Denosumab

When secondary hyperparathyroidism in CKD is refractory to phosphate binders and vitamin D analogues (and calcium is not elevated), cinacalcet (a calcimimetic) should be added. Cinacalcet activates the calcium-sensing receptor on parathyroid cells, reducing PTH secretion without increasing calcium or phosphate. It is PBS-listed for CKD patients on dialysis with uncontrolled secondary hyperparathyroidism. The EVOLVE trial showed a trend towards reduced cardiovascular events. Surgical parathyroidectomy is reserved for refractory cases.

Reference: KHA-CARI – 2013 – CKD-MBD Guidelines; KDIGO – 2017 – CKD-MBD Update