Spaia S
Nephrology Department,2 Hospital of IKA,Thessaloniki, Greece.
Hippokratia. 2011 Jan;15(Suppl 1):22-6.
In chronic kidney disease patients, bone and mineral abnormalities have a major impact on morbidity and mortality. Hyperphosphatemia has been associated with increased mortality and with the development of cardiovascular calcification, an independent predictor of mortality. Sevelamer, or more precisely 'sevelamer hydrochloride', is a weakly basic anion-exchange resin in the chloride form that was introduced in 1997 for the treatment of the hyperphosphataemia of patients with end-stage renal failure. Sevelamer sequesters phosphate within the gastrointestinal tract, so prevents its absorption and enhances its faecal excretion. Over the succeeding years, large numbers of patients have been treated with sevelamer, and it has fulfilled expectations in helping to control the hyperphosphataemia of end-stage renal failure. Additionally treatment with sevelamer was accompanied with lower incidence of hypercalcemia, decreased incidence of low PTH levels, a 15-31% decrease of LDL-cholesterol both in dialysis and predialysis patients, decreased C-reactive protein, amelioration of hyperuricemia and low fetuin A, decrease of uremic toxins, suggesting an overall anti-inflammatory effect. In incident dialysis patients, treatment with sevelamer has been associated with better survival, while in prevalent patients a clear benefit could only be demonstrated in older patients and in patients treated for more than 2 years. In dialysis patients, the treatment of hyperphospathemia with calcium based compounds, when compared with sevelamer, is associated with more frequent episodes of hypercalcemia, suppression of intact PTH and with progression of coronary calcifications. In the presence of adynamic bone disease, calcium load has a significantly higher impact on aortic calcifications and stiffening. Sevelamer treatment resulted in no statistically significant changes in bone turnover or mineralization compared with calcium carbonate, but bone formation rate increased and trabecular architecture improved only with sevelamer. In conclusion, the treatment of hyperphosphatemia with sevelamer hydrochloride, a noncalcium and non-metal containing phosphate binder, is associated with a beneficial effect on vascular calcification progression, bone disease and most likely with a survival benefit in some hemodialysis patients populations. Sevelamer carbonate is an improved, buffered form of sevelamer hydrochloride developed for the treatment of hyperphosphataemia in CKD patients. Sevelamer carbonate formulated as a powder for oral suspension presents a novel, patient- friendly alternative to tablet phosphate binders. Safety and efficacy of sevelamer carbonate powder compared with sevelamer hydrochloride tablets in CKD patients are equivalent, with Sevelamer carbonate having fewer side effects from gastrointestinal tract.
在慢性肾脏病患者中，骨与矿物质异常对发病率和死亡率有重大影响。高磷血症与死亡率增加以及心血管钙化的发生相关，而心血管钙化是死亡率的独立预测因素。司维拉姆，更准确地说是“盐酸司维拉姆”，是一种氯化物形式的弱碱性阴离子交换树脂，于1997年被引入用于治疗终末期肾衰竭患者的高磷血症。司维拉姆在胃肠道内螯合磷酸盐，从而阻止其吸收并增加其粪便排泄。在随后的几年里，大量患者接受了司维拉姆治疗，并且它在帮助控制终末期肾衰竭的高磷血症方面达到了预期效果。此外，司维拉姆治疗伴随高钙血症发生率降低、低甲状旁腺激素水平发生率降低、透析患者和透析前患者的低密度脂蛋白胆固醇水平降低15% - 31%、C反应蛋白降低、高尿酸血症和低胎球蛋白A改善、尿毒症毒素减少，提示具有总体抗炎作用。在新发透析患者中，司维拉姆治疗与更好的生存率相关，而在长期透析患者中，仅在老年患者和治疗超过2年的患者中显示出明显益处。在透析患者中，与司维拉姆相比用含钙化合物治疗高磷血症与更频繁的高钙血症发作、完整甲状旁腺激素的抑制以及冠状动脉钙化进展相关。在存在动力缺失性骨病的情况下，钙负荷对主动脉钙化和僵硬有显著更高的影响。与碳酸钙相比，司维拉姆治疗导致骨转换或矿化无统计学显著变化，但仅司维拉姆使骨形成率增加且小梁结构改善。总之，用不含钙和金属的磷酸盐结合剂盐酸司维拉姆治疗高磷血症对血管钙化进展、骨病有有益作用，并且很可能对一些血液透析患者群体有生存益处。碳酸司维拉姆是为治疗CKD患者的高磷血症而开发的盐酸司维拉姆的改良、缓冲形式。制成口服混悬液粉末形式的碳酸司维拉姆是片剂磷酸盐结合剂的一种新型、对患者友好的替代品。在CKD患者中，碳酸司维拉姆粉末与盐酸司维拉姆片剂相比的安全性和有效性相当，碳酸司维拉姆的胃肠道副作用更少。
