Sprague Stuart M, Llach Francisco, Amdahl Michael, Taccetta Carol, Batlle Daniel
Division of Nephrology/Hypertension and Department of Medicine, Northwestern University Feinberg School of Medicine, Evanston, Illinois 60201, USA.
Kidney Int. 2003 Apr;63(4):1483-90. doi: 10.1046/j.1523-1755.2003.00878.x.
Management of secondary hyperparathyroidism has included the use of active vitamin D or vitamin D analogs for the suppression of parathyroid hormone (PTH) secretion. Although, these agents are effective, therapy is frequently limited by hypercalcemia, hyperphosphatemia, and/or elevations in the calcium-phosphorus (Ca x P) product. In clinical studies, paricalcitol was shown to be effective at reducing PTH concentrations without causing significant hypercalcemia or hyperphosphatemia as compared to placebo. A comparative study was undertaken in order to determine whether paricalcitol provides a therapeutic advantage to calcitriol.
A double-blind, randomized, multicenter study comparing the safety and effectiveness of intravenous paricalcitol and calcitriol in suppressing PTH concentrations in hemodialysis patients was performed. A total of 263 randomized patients were enrolled at domestic and international sites. Following the baseline period, patients with serum Ca x P < 75, and a PTH level > or =300 pg/mL were randomly assigned to receive either paricalcitol or calcitriol in a dose-escalating fashion for up to 32 weeks. Dose adjustments were based on laboratory results for PTH, calcium, and Ca x P. The primary end point was the greater than 50% reduction in baseline PTH. Secondary end points were the occurrence of hypercalcemia and elevated Ca x P product.
Paricalcitol-treated patients achieved a > or =50% reduction from baseline PTH significantly faster than did the calcitriol-treated patients (P = 0.025) and achieved a mean reduction of PTH into a desired therapeutic range (100 to 300 pg/mL) at approximately week 18, whereas the calcitriol-treated patients, as a group, were unable to achieve this range. Moreover, paricalcitol-treated patients had significantly fewer sustained episodes of hypercalcemia and/or increased Ca x P product than calcitriol patients (P = 0.008).
Paricalcitol treatment reduced PTH concentrations more rapidly with fewer sustained episodes of hypercalcemia and increased Ca x P product than calcitriol therapy.
继发性甲状旁腺功能亢进的治疗方法包括使用活性维生素D或维生素D类似物来抑制甲状旁腺激素（PTH）的分泌。尽管这些药物有效，但治疗常常受到高钙血症、高磷血症和/或钙磷（Ca×P）乘积升高的限制。在临床研究中，与安慰剂相比，帕立骨化醇被证明在降低PTH浓度方面有效，且不会引起明显的高钙血症或高磷血症。进行了一项比较研究，以确定帕立骨化醇是否比骨化三醇具有治疗优势。
进行了一项双盲、随机、多中心研究，比较静脉注射帕立骨化醇和骨化三醇在抑制血液透析患者PTH浓度方面的安全性和有效性。共有263名随机入组的患者在国内和国际多个地点入组。在基线期之后，血清Ca×P<75且PTH水平≥300 pg/mL的患者被随机分配，以剂量递增的方式接受帕立骨化醇或骨化三醇治疗，最长治疗32周。剂量调整基于PTH、钙和Ca×P的实验室检查结果。主要终点是基线PTH降低超过50%。次要终点是高钙血症的发生和Ca×P乘积升高。
与骨化三醇治疗的患者相比，帕立骨化醇治疗的患者从基线PTH降低≥50%的速度明显更快（P = 0.025），并且在大约第18周时PTH平均降低至理想的治疗范围（100至300 pg/mL），而骨化三醇治疗的患者作为一个整体未能达到该范围。此外，帕立骨化醇治疗的患者发生高钙血症和/或Ca×P乘积升高的持续发作明显少于骨化三醇治疗的患者（P = 0.008）。
与骨化三醇治疗相比，帕立骨化醇治疗能更迅速地降低PTH浓度，且高钙血症和Ca×P乘积升高的持续发作更少。
