What is cinacalcet and when is it used in CKD-MBD?

• A. A calcimimetic that enhances CaSR sensitivity, suppressing PTH in secondary/tertiary hyperparathyroidism.
• B. A vitamin D analog that increases calcium absorption.
• C. A bisphosphonate that inhibits osteoclasts.
• D. A loop diuretic that increases calcium excretion.

Answer: (B)

Cinacalcet is a calcimimetic agent. It works by increasing the sensitivity of the calcium-sensing receptor on parathyroid cells to extracellular calcium, so the parathyroid gland reduces PTH secretion. In CKD-MBD, secondary hyperparathyroidism drives high PTH levels that contribute to bone disease and abnormal mineral balance; lowering PTH helps normalize bone turnover and can reduce complications related to hyperparathyroidism. Clinically, cinacalcet is used in chronic kidney disease patients, particularly those on dialysis, who have persistent secondary hyperparathyroidism. It can also be utilized in tertiary hyperparathyroidism when surgery isn’t feasible or fails to control PTH. It is not a vitamin D analog and does not act by increasing intestinal calcium absorption, nor is it a bisphosphonate or a loop diuretic.