칼시트리올

Predialysis Patients Calcitriol is indicated in the management of secondary hyperparathyroidism and resultant metabolic bone disease in patients with moderate to severe chronic renal failure (Ccr 15 to 55 mL/min) not yet on dialysis. In children, the creatinine clearance value must be corrected for a surface area of 1.73 square meters. A serum iPTH level of ≥ 100 pg/mL is strongly suggestive of secondary hyperparathyroidism. Dialysis Patients Calcitriol is indicated in the management of hypocalcemia and the resultant metabolic bone disease in patients undergoing chronic renal dialysis. In these patients, calcitriol administration enhances calcium absorption, reduces serum alkaline phosphatase levels, and may reduce elevated parathyroid hormone levels and the histological manifestations of osteitis fibrosa cystica and defective mineralization. Hypoparathyroidism Patients Calcitriol is also indicated in the management of hypocalcemia and its clinical manifestations in patients with postsurgical hypoparathyroidism, idiopathic hypoparathyroidism, and pseudohypoparathyroidism.

Calcitriol should not be given to patients with hypercalcemia or evidence of vitamin D toxicity. Use of calcitriol in patients with known hypersensitivity to calcitriol (or drugs of the same class) or any of the inactive ingredients is contraindicated.

Overdosage of any form of vitamin D is dangerous (see OVERDOSAGE ). Progressive hypercalcemia due to overdosage of vitamin D and its metabolites may be so severe as to require emergency attention. Chronic hypercalcemia can lead to generalized vascular calcification, nephrocalcinosis and other soft-tissue calcification. The serum calcium times phosphate (Ca x P) product should not be allowed to exceed 70 mg 2 /dL 2 . Radiographic evaluation of suspect anatomical regions may be useful in the early detection of this condition. Calcitriol is the most potent metabolite of vitamin D available. The administration of calcitriol to patients in excess of their daily requirements can cause hypercalcemia, hypercalciuria, and hyperphosphatemia. Therefore, pharmacologic doses of vitamin D and its derivatives should be withheld during calcitriol treatment to avoid possible additive effects and hypercalcemia. If treatment is switched from ergocalciferol (vitamin D 2 ) to calcitriol, it may take several months for the ergocalciferol level in the blood to return to the baseline value (see OVERDOSAGE ). Calcitriol increases inorganic phosphate levels in serum. While this is desirable in patients with hypophosphatemia, caution is called for in patients with renal failure because of the danger of ectopic calcification. A nonaluminum phosphate-binding compound and a low-phosphate diet should be used to control serum phosphorus levels in patients undergoing dialysis. Magnesium-containing …

Calcitriol has been found to be teratogenic in rabbits when given at doses of 0.08 and 0.3 mcg/kg (approximately 2 and 6 times the maximum recommended dose based on mg/m 2 ). All 15 fetuses in 3 litters at these doses showed external and skeletal abnormalities. However, none of the other 23 litters (156 fetuses) showed external and skeletal abnormalities compared with controls. Teratogenicity studies in rats at doses up to 0.45 mcg/kg (approximately 5 times maximum recommended dose based on mg/m 2 ) showed no evidence of teratogenic potential. There are no adequate and well-controlled studies in pregnant women. Calcitriol should be used during pregnancy only if the potential benefit …