Which therapy option is a calcimimetic used to control secondary hyperparathyroidism in CKD-MBD?

• A. Cinacalcet
• B. Sevelamer
• C. Calcitriol
• D. Calcium carbonate

Answer: (A)

Calcimimetics work by increasing the sensitivity of the calcium-sensing receptor on parathyroid cells, which lowers PTH secretion in response to circulating calcium. Cinacalcet does exactly this, acting as a calcimimetic to reduce secondary hyperparathyroidism in CKD-MBD. It directly modulates the parathyroid gland’s response to calcium, helping control PTH without raising calcium or phosphate levels.

Sevelamer is a phosphate binder, aimed at lowering phosphate but not at suppressing PTH via the calcium-sensing receptor. Calcitriol is an active vitamin D analog that can suppress PTH but increases calcium and phosphate absorption, potentially worsening mineral balance. Calcium carbonate is a calcium-based phosphate binder that also raises calcium load rather than modulating CaSR. Thus, cinacalcet is the calcimimetic used for this purpose.