[New therapeutic strategies in secondary hyperparathyroidism on dialysis (II): vitamin D analogues and calcium-mimetics]

Abstract

Secondary hyperparathyroidism (SHP) is a frequent complication of dialysis patients. In this second article we will analyze the new vitamin D analogs, capable of decreasing parathyroid hormone (PTH) levels with a lower effect on intestinal calcium and phosphorus absorption. Among other advantages described in the experimental setting, paricalcitol shows a survival benefit in dialysis patients as compared to calcitriol, at least in retrospective studies, and thus it became our first-line vitamin D derivative. Calcimimetics are unique since they decrease PTH levels without increasing serum calcium and phosphorus. Actually, calcium and phosphorus decrease in a significant number of patients. These drugs will soon be authorized in Spain, and we describe the better achievement of K/DOQI guidelines as well as other beneficial effects observed in the experimental animal with them. Finally, we mention the potential benefit of mild metabolic acidosis, the use of bisphosphonates, the role of bone morphogenetic protein BMP-7, and the use of teriparatide. The future treatment of SHP will probably require the independent management of calcium, phosphorus, vitamin D and PTH. Thus, low-dose combined treatments with selective drugs may prove more effective than sequential therapies.