A comparison of oral and intravenous alfacalcidol in the treatment of uremic hyperparathyroidism.
The i.v. bolus administration of 1 alpha hydroxylated vitamin D derivatives is effective in the treatment of uremic hyperparathyroidism. However, few of the published studies of this mode of treatment have been adequately controlled, and recent reports have suggested that p.o. bolus administration may be just as effective. In this study, 16 hemodialysis patients with mild to moderate hyperparathyroidism were assigned, after a 4-wk run-in period, to receive a 6-wk course of either thrice-weekly i.v. or p.o. alfacalcidol (initial dose, 4 micrograms). Then, after a further control period, they received a second 6-wk course, with either p.o. or i.v. alfacalcidol (whichever was not given in the first treatment period). Plasma parathyroid hormone (PTH) was measured weekly by the use of an intact hormone assay. Both routes of therapy resulted in a significant suppression of plasma PTH (P = 0.005) and an elevation in plasma ionized calcium (P = 0.01). The magnitude of the responses was similar for the two treatment phases, as was the relationship between the increment in calcium and the decrement in PTH. The most complete suppression of PTH was seen in those with the greatest increment in plasma calcium. The incidence of hypercalcemia and the mean dose reductions necessary were also similar in the two treatment phases. Oral bolus therapy and i.v. bolus therapy with alfacalcidol are equally effective in suppressing hyperparathyroidism. The postulated advantages of i.v. over p.o. therapy with 1 alpha hydroxylated vitamin D derivatives remain to be confirmed by controlled studies.
Lee
W T
WT
Department of Medicine, Auckland Hospital, New Zealand.
Padayachi
K
K
Collins
J F
JF
Cundy
T
T
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D002118:Calcium / Q000097:blood; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D006887:Hydroxycholecalciferols / Q000008:administration & dosage* / Q000627:therapeutic use; D006962:Hyperparathyroidism, Secondary / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D007262:Infusions, Intravenous; D007676:Kidney Failure, Chronic / Q000150:complications; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D014511:Uremia / Q000150:complications*
D006887:Hydroxycholecalciferols; D010281:Parathyroid Hormone; D002118:Calcium; C008088:alfacalcidol