Cinacalcet: pharmacological and clinical aspects

The calcium sensing receptor (CaSR) is expressed in cells secreting calcium-regulating hormones, in cells involved in calcium transport and in many other tissues, with an as yet not completely defined role. In parathyroid cells, the CaSR stimulation inhibits parathyroid hormone (PTH) secretion, synthesis and parathyroid cell proliferation. Cinacalcet belongs to calcimimetic type II compounds that can interact with CaSR, increasing its affinity for calcium. Clinical studies have proved cinacalcet to be effective in reducing calcium and PTH levels in primary hyperparathyroidism and in reducing PTH, calcium and phosphate in patients with secondary hyperparathyroidism owing to chronic renal failure, with a relatively safe profile, the only reported adverse events being hypocalcaemia and gastrointestinal symptoms. However, though calcimimetics do represent a real advancement in the field of the treatment of PTH secretion disturbances, there is a need for clinical trials, which should aim to demonstrate that a better control of biochemical parameters is also matched with better clinical outcomes.