Secondary hyperparathyroidism in
chronic renal failure (CRF) is due to the increased activity of parathyroid gland. The negative feedback control exerted by the
vitamin D metabolite 1,25 (
OH)2 D3 is lacking due to the deficiency of this metabolite in CRF. We have studied whether
alphacalcidol given orally as thrice weekly evening pulses lowers
parathyroid hormone (PTH) levels of children with CRF.
Alphacalcidol 0.5-3.0 micrograms was given thrice weekly orally to a total of 22 children (mean age 5.6 years) with CRF; the dosis was adjusted according to PTH, ionized
calcium and
phosphate concentration. Serum PTH decreased significantly from a pretreatment level of 393 +/- 81 to 122 +/- 34 ng/l after 12 months, and stabilized at this level. Mean
vitamin D metabolite concentrations were within normal range. 1,25 dihydroxyvitamin D did not increase during
therapy while PTH decreased. The estimated
creatinine clearance remained nearly the same (20 +/- 3 and 21 +/- 6 ml/min/ 1.73 m2). Growth remained low normal and bone mineral density did not decrease. Oral
alphacalcidol pulse
therapy for
hyperparathyroidism in uremic children seemed to be easy and effective. The response is even better in inhibiting potential autonomous parathyroid
hyperplasia if this treatment was started early. We conclude that feedback regulation of PTH with oral
alphacalcidol pulse
therapy is efficient in the treatment of
hyperparathyroidism in children with CRF prior to dialysis.