PULSE ORAL VERSUS INTRAVENOUS CALCITRIOL THERAPY IN CHRONIC-HEMODIALYSIS PATIENTS - A PROSPECTIVE AND RANDOMIZED STUDY

The aim of this prospective and randomized study was to compare the ef ficacy, side effects, and costs of 'pulse oral' versus intravenous cal citriol in the treatment of secondary hyperparathyroidism in hemodialy sis (HD) patients. A total of 20 patients were randomized to receive o ver a 4-month period pulse orally administered calcitriol (pulse oral group; n = 10) or intravenous calcitriol (intravenous group; n = 10). All patients used standard dialysate calcium (1.75 mmol/l) throughout the study period. In accordance with the study design calcium dialysat e concentrations were reduced when this was necessary to avoid hyperca lcemic crises. The patients were stratified into two subgroups accordi ng to their initial serum PTH levels: patients with mild or moderate d egree of hyperparathyroidism (17 patients) and patients with severe hy perparathyroidism (3 patients). Intravenous and pulse oral cacitriol d id not significantly reduce serum PTH concentrations in patients with severe hyperparathyroidism (1,157 +/- 156 vs. 807 +/- 228 ng/ml, p = 0 .09). Intermittent calcitriol, administered by intravenous or oral rou te, significantly reduced serum PTH levels (326 +/- 119 vs. 109 +/- 79 ng/ml, p = 0.0001) in patients with mild or moderate hyperparathyroid ism. In patients with mild or moderate hyperparathyroidism, intravenou s calcitriol significantly reduced PTH concentrations at the end of th e Ist month, before the increase of serum ionized calcium levels, wher eas 'pulse oral' calcitriol significantly suppressed parathyroid activ ity at the end of the 2nd month. Calcium dialysate concentration was r educed in 9 out of 10 (90%) patients of the pulse oral group and in al l patients (10/10) of intravenous group. The incidence of hypercalcemi c crises was 24% (39/160) in the pulse oral group and 14% (27/160) in the intravenous group. Analysis of costs showed that intravenous calci triol was more expensive compared to pulse oral calcitriol. These data indicate that intermittent intensive calcitriol therapy, regardless o f the route of administration, is effective in suppressing parathyroid activity in HD patients with mild or moderate hyperparathyroidism. In contrast, intermittent calcitriol therapy has a limited ability to ac hieve sustained serum PTH reductions in HD patients with severe hyperp arathyroidism. Intravenous calcitriol was more expensive than pulse or al calcitriol, and we recommend the use of pulse oral calcitriol in HD patients with mild or moderate secondary hyperparathyroidism.