LOW CALCIUM DIALYSATE AND HIGH-DOSE ORAL CALCITRIOL IN THE TREATMENT OF SECONDARY HYPERPARATHYROIDISM IN HEMODIALYSIS-PATIENTS

We treated nineteen haemodialysis patients with secondary hyperparathyroidism with increasing oral doses of 1,25 dihydroxycholecalciferol (calcitriol) over a 12-week period and used low calcium dialysate (1.0 mmol/l) to prevent hypercalcaemia. Nine patients received daily calcitriol and ten received calcitriol thrice weekly, and at the end of the study the mean doses were 2.0-mu-g daily and 2.6-mu-g thrice weekly respectively. The regimen was well tolerated with nine episodes of mild hypercalcaemia, none of which were symptomatic. Mean PTH and alkaline phosphatase concentrations decreased from 62.0 pmol/l(15-125) to 22.0 pmol/l(1-70) (P < 0.01), and 144 IU/l (48-461) to 123 IU/l (61-346) (P < 0.05) respectively. Mean serum calcium increased from 2.33 mmol/l (2.05-2.55) to 2.52 mmol/l (2.26-2.67) (P < 0.01). There were no significant changes in serum phosphate, magnesium, or aluminium concentrations and there were no significant differences in outcome between patients receiving daily therapy compared to those receiving it thrice weekly. A combination of high-dose oral calcitriol and low calcium dialysate can reverse secondary hyperparathyroidism without causing hypercalcaemia and these results suggest a benefit over conventional low-dose calcitriol.