Description Cinacalcet (INN) is a drug that acts as a calcimimetic (i.e. it mimics the action of calcium on tissues) by allosteric activation of the calcium-sensing receptor that is expressed in various human organ tissues. Indication For the treatment of secondary hyperparathyroidism in patients with Chronic Kidney Disease who are on hemodialysis or peritoneal dialysis. Also for the treatment of hypercalcemia in patients with parathyroid carcinoma. Mechanism of action The calcium-sensing receptors on the surface of the chief cell of the parathyroid gland is the principal regulator of parathyroid hormone secretion (PTH). Cinacalcet directly lowers parathyroid hormone levels by increasing the sensitivity of the calcium sensing receptors to activation by extracellular calcium, resulting in the inhibition of PTH secretion. The reduction in PTH is associated with a concomitant decrease in serum calcium levels.