Warnings: Since calcitriol is the most potent metabolite of vitamin D available, vitamin D and its derivatives should be withheld during treatment. A non-aluminum phosphate-binding compound should be used to control serum phosphorus levels in patients undergoing dialysis.
Overdosage of any form of vitamin d is dangerous (see also 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.
Radiographic evaluation of suspect anatomical regions may be useful in the early detection of this condition.
Precautions: Excessive dosage of Bonky (calcitriol injection) induces hypercalcemia and in some instances hypercalciuria: Therefore, early in treatment during dosage adjustment, serum calcium and phosphorus should be determined at least twice weekly. Should hypercalcemia develop, the drug should be discontinued immediately. Bonky should be given cautiously to patients on digitalis, because hypercalcemia in such patients may precipitate cardiac arrhythmias.
Information for the patient: The patient and his or her parents should be informed about adherence to instructions about diet and calcium supplementation and avoidance of the use of unapproved non-prescription drugs, including magnesium-containing antacids. Patients should also be carefully informed about the symptoms of hypercalcemia (see ADVERSE REACTIONS).
Essential laboratory tests: Serum calcium, phosphorus, magnesium and alkaline phosphatase and 24-hour urinary calcium and phosphorus should be determined periodically. During the initial phase of the medication, serum calcium and phosphorus should be determined more frequently (twice weekly).
Because the effect of calcitriol in the treatment of bone loss after implantation has not been established, this drug should not be used.
Because the effect of calcitriol in patients with post menopausal osteoporosis cause by decrease of estrogen have not been established, this drug should not be used.
Others: Carcinogenesis, mutagenesis, impairment of fertility: Long-term studies in animals have not been performed to evaluate the carcinogenic potential of Bonky (calcitriol).
There was no evidence of mutagenicity as studies by the Ames Method.
No significant effects of calcitriol on fertility were reported using oral calcitriol.
Use in Children: Safety and efficacy of Bonky in children have not been established.