ORAL CALCITRIOL VERSUS ORAL ALFACALCIDOL FOR THE TREATMENT OF SECONDARY HYPERPARATHYROIDISM IN PATIENTS RECEIVING HEMODIALYSIS: A RANDOMIZED, CROSSOVER TR IAL

Main Article Content

Samantha Moe
Lori D Wazny
Janet E Martin

Keywords

Vitamin D analogues, alfacalcidol, calcitriol, secondary hyperparathyroidism, renal dialysis

Abstract

Background


Secondary hyperparathyroidism  is a common complication in patients with chronic kidney disease and treatment with vitamin D analogues is a mainstay of therapy. Although oral calcitriol and alfacalcidol are used extensively in Canada, there is little published data comparing equal doses of these agents.


 


Objectives


To compare the effect of equal doses of oral calcitriol and alfacalcidol on intact parathyroid hormone concentrations (iPTH) in the treatment of secondary hyperparathyroidism due to chronic kidney disease.


Secondary endpoints included serum 1,25-dihydroxyvitamin  D3, calcium and phosphate concentrations, achievement of target iPTH concentrations, and need for phosphate binder dose increases.


 


Methods


Five adult hemodialysis subjects who were naïve to vitamin D analogues and had iPTH concentrations ³


20 pmol/L were enrolled  in a prospective,  randomized  16-week  crossover  pilot study.  Subjects  were randomized to either oral calcitriol or oral alfacalcidol 0.75 mcg three times weekly for six weeks. After a four-week washout period, patients were crossed over to the alternate drug for six weeks.


 


Results


Oral calcitriol significantly suppressed iPTH after six weeks of therapy (p=0.003), while no significant change in iPTH was observed with oral alfacalcidol.


 


Conclusions


This small randomized crossover study provides preliminary evidence that equal doses of oral alfacalcidol and calcitriol  may demonstrate  differences  in iPTH suppression  during the first six weeks in dialysis patients treated for secondary hyperparathyroidism. Further comparative trials are required to confirm this finding and to determine whether important differences in parathyroid hormone suppression exist between


oral calcitriol and alfacalcidol beyond the six-week period.

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