Gallagher J C
Bone Metabolism Unit, Creighton University Medical Center, Saint Joseph's Hospital, Omaha, NE 68131.
Metabolism. 1990 Apr;39(4 Suppl 1):27-9. doi: 10.1016/0026-0495(90)90268-h.
The long-term safety and efficacy of synthetic 1,25-(OH)2D3 (calcitriol; Rocaltrol) in the treatment of women with type 1 osteoporosis is being assessed in a randomized trial. Patients were allocated in double-blind fashion to 1,25-(OH)2D3 or matching placebo. Initially, the calcium intake was adjusted to 1,000 mg/d. The study protocol called for increasing the dose of 1,25-(OH)2D3 until patients developed either hypercalcemia or hypercalciuria. However, in order to maintain a higher dose of calcitriol on a long-term basis, the calcium intake had to be reduced to 600 mg/d in those receiving calcitriol; if that was not successful in eliminating hypercalcemia and hypercalciuria, then the dose of 1,25-(OH)2D3 was reduced as necessary. During the hypercalcemic phase, the indices of bone resorption decreased significantly, demonstrating that calcium absorption is solely responsible for hypercalcemia. The maintenance dose was established after 8 to 10 weeks, and the 24-hour urine calcium and creatinine clearance remained constant throughout the remainder of the study period. On a calcium intake of 600 mg/d, the long-term maintenance dose of 1,25-(OH)2D3 averaged 0.675 micrograms/d. Long-term therapy on an average dose of 0.675 micrograms/d was not associated with nephrotoxicity.
一项随机试验正在评估合成的1,25 - (OH)₂D₃（骨化三醇；罗钙全）治疗1型骨质疏松症女性的长期安全性和疗效。患者以双盲方式被分配接受1,25 - (OH)₂D₃或匹配的安慰剂。最初，钙摄入量调整为1000mg/d。研究方案要求增加1,25 - (OH)₂D₃剂量，直到患者出现高钙血症或高钙尿症。然而，为了长期维持较高剂量的骨化三醇，接受骨化三醇治疗的患者钙摄入量不得不降至600mg/d；如果这不能成功消除高钙血症和高钙尿症，则根据需要减少1,25 - (OH)₂D₃剂量。在高钙血症阶段，骨吸收指标显著下降，表明钙吸收是高钙血症的唯一原因。在8至10周后确定维持剂量，并且在研究期的剩余时间内24小时尿钙和肌酐清除率保持恒定。在钙摄入量为600mg/d时，1,25 - (OH)₂D₃的长期维持剂量平均为0.675微克/d。平均剂量为0.675微克/d的长期治疗与肾毒性无关。
