Hyperparathyroidism calcimimetics

A class of allosteric activators of the Ca2+-sensing receptor that sensitizes the receptor to extracellular calcium and acts only in the presence but not in the absence of calcium. Calcimimetics can be used to treat various forms of hyperparathyroidism, although they are only approved for use in patients with end stage renal disease receiving dialysis treatment. 

Paricalcitol is a synthetically manufactured analogue of calcitriol. It is indicated for the prevention and treatment of secondary hyperparathyroidism in chronic kidney disease. Cinacalcet, a drug that acts as a calcimimetic, can be added if the effects on PTH levels are isufficient. 

This rather common disease, if associated with symptoms and significant hypercalcemia, is best treated surgically. Oral phosphate and bisphosphonates have been tried but cannot be recommended. Asymptomatic patients with mild disease often do not get worse and may be left untreated. The calcimimetic agent cinacalcet, discussed previously, has been approved for secondary hyperparathyroidism and is in clinical trials for the treatment of primary hyperparathyroidism. If such drugs prove efficacious, medical management of this disease will need to be reconsidered. 

Cinacalcet (Sensipar) [Hyperparathyroidism Agent/ Calcimimetic] Uses Secondary hyperparathyroidism in CRF T Ca2+ in parathyroid carcinoma Action 4- PTH by T Ca-sensing receptor sensitivity Dose ... 

Dong BJ. Cinacalcet An oral calcimimetic agent for the management of hyperparathyroidism. Clin Ther. 2005 27 1725-1751. 

Lmdberg JS, Moe SM, Goodman WG, Coburn JW, Sprague SM, Liu W, et al. The calcimimetic AMG 073 reduces parathyroid hormone and calcium x phosphorus in secondary hyperparathyroidism. Kidney Int 2003 63 248-54. 

Quarles LD, et al. The calcimimetic AMG 073 as a potential treatment for secondary hyperparathyroidism of end-stage renal disease. J Am Soc Nephrol 2003 14 575-583. 

Franceschini N, Joy MS, Kshirsagar A. Cincacet HCl a calcimimetic agent for the management of primary and secondary hyperparathyroidism. Expert Opin Investig Drugs 2003 12 1413-1421. 

Cinacalcet is a calcimimetic agent that lowers parathyroid hormone (PTH) levels by increasing sensing receptor to extracellular calcium. This drug is indicated in the treatment of secondary hyperparathyroidism in patients with chronic kidney disease on dialysis and hypercalcemia in patients with parathyroid carcinoma. 

Calcimimetics mimic the action of calcium via the CaSR to inhibit PTH secretion by the parathyroid glands. Because of this enhanced sensitivity, they decrease PTH secretion for any given level of Ca. The calcimimetic cinacalcet (sensipar) is FDA-approved for the treatment of secondary hyperparathyroidism due to chronic renal disease and for patients with hypercalcemia associated with parathyroid carcinoma (Figure 61-9). In clinical trials, cinacalcet also effectively reduced PTH levels in patients with primary hyperparathyroidism and normalized serum calcium without altering bone mineral density for up to 2 years. 

In six cases of hthium-associated hyperparathyroidism, four had parathyroid adenomas [67, 68 ]. The authors suggested that lithium can help uncover pre-existing parathyroid disease, although there does appear to be an increased incidence of multiglandular or multiadenomatous disease in patients taking lithium. Surgical treatment is often curative when adenomas are discovered. When hypercalcemia persists, cinacalcet, a calcimimetic can be used effectively. 

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