Calcimimetica

Calcimimetics are a class of drugs that act as positive allosteric modulators of the calcium-sensing receptor (CaSR). By increasing the receptor’s sensitivity to extracellular calcium, they suppress the secretion of parathyroid hormone (PTH). The resulting reduction in PTH helps lower serum calcium and modulate phosphate balance in disorders of calcium-phosphate homeostasis.

The two main agents are cinacalcet and etelcalcetide. Cinacalcet is an oral small molecule used primarily to treat secondary hyperparathyroidism in patients with chronic kidney disease, especially those on dialysis. Etelcalcetide is a peptide administered intravenously after hemodialysis and is also used to control secondary hyperparathyroidism in adults. Both drugs reduce PTH levels by enhancing CaSR activity in the parathyroid glands, with secondary effects on calcium and phosphate balance.

Indications and use vary by region and patient condition. Cinacalcet is approved for hyperparathyroidism related to CKD and, in some cases, hypercalcemia due to parathyroid carcinoma; etelcalcetide is specifically indicated for adults with CKD on dialysis and persistent SHPT. Calcimimetics may be used when surgery or other treatments are unsuitable or incomplete, and they can be part of a broader strategy to manage bone-mineral disorders in CKD.

Safety and monitoring considerations are important. The principal adverse effect is hypocalcemia, which requires regular monitoring of calcium, phosphate, and PTH levels. Common non-serious events include nausea, vomiting, and dizziness. Cinacalcet is contraindicated in hypocalcemia; clinicians adjust therapy based on electrolyte and hormonal responses and interactions with other medications.