Drug Class Description
Vitamin D analogues (vitamins).

Generic Name
Calcitriol

Drug Description
Calcijex 1 microgram/ml Solution for Injection

Presentation
Solution for Injection

Indications
Calcijex is indicated in the management of hypocalcaemia in patients undergoing dialysis for chronic renal failure. It has been shown to significantly reduce elevated parathyroid hormone (PTH) levels. Reduction of PTH has been shown to result in an improvement in renal osteodystrophy.

Adult Dosage
The optimal dose of Calcijex must be carefully determined for each patient.The effectiveness of Calcijex therapy is predicted on the assumption that each patient is receiving an adequate and appropriate daily intake of calcium. To ensure that each patient receives an adequate daily intake of calcium, the physician should either prescribe a calcium supplement, or instruct the patient in proper dietary measures.The recommended initial dose of Calcijex is 0.50 microgram (approximately 0.01 microgram/kg) administered three times weekly, approximately every other day. Calcijex can be administered as a bolus dose intravenously through the catheter at the end of haemodialysis. If a satisfactory response in the biochemical parameters and clinical manifestations of the disease state is not observed, the dose may be increased by 0.25 to 0.50 microgram increments at two to four week intervals. During this titration period, serum calcium and phosphate levels should be obtained at least twice weekly, and if hypercalcaemia is noted, or a serum calcium times phosphate greater than 7-8 mmol/l is noted, the drug should be immediately discontinued until these parameters are normal. Then the Calcijex dose should be reinitiated at a lower dose. Most patients undergoing haemodialysis respond to doses of between 0.5 and 3.0 microgram three times per week. Incremental dosing must be individualised and commensurate with PTH, serum calcium and phosphorus levels.Dialysis patients with moderate to severe secondary hyperparathyroidism Based on limited data from clinical trials with dialysis patients with moderate to severe secondary hyperparathyroidism, an initial dose, depending on the severity of secondary hyperparathyroidism, of 1.0 to 2.0 microgram administered three times weekly approximately every other day may be considered in this group of patients. Doses as small as 0.5 microgram and as large as 4.0 microgram thrice weekly have been used as an initial dose in this group, depending on the severity of the hyperparathyroidism. If a satisfactory response in the biochemical parameters and clinical manifestations of the disease state is not observed, the dose may be increased by 0.25 to 0.5 microgram at two to four week intervals. Incremental dosing from 0.25 microgram to 2.0 microgram has been used and maximal doses up to 8 microgram three times per week have been reported in a small number of patients with severe secondary hyperparathyroidism. Close biochemical monitoring and other advice detailed above are essential during therapy, in particular during dose titration. Doses may need to be reduced as the PTH levels decrease in response to the therapy. Parathyroidectomy may be considered in patients with severe secondary hyperparathroidism, refractory to all standard treatment.Higher doses of Calcijex may be required for patients taking barbiturates or anticonvulsants as these may reduce its effects. The effects of Calcijex may be counteracted by c