EFFECTS OF ORAL VS INTRAVENOUS CALCITRIOL ON SERUM PARATHYROID-HORMONE LEVELS IN CHRONIC-HEMODIALYSIS PATIENTS

The effects of oral vs. intravenous calcitriol on suppression of serum intact parathyroid hormone (iPTH) in a selected group of chronic hemo dialysis patients were observed over a several month period. Both form ulations of calcitriol were associated with significant increases in s erum calcium (oral: 9.2 +/- .2 mg/dL to 10.5 +/- .4 mg/dL, P<0.05, vs. intravenous: 9.1 +/- .2 mg/dL to 10.3 +/- .3 mg/dL, P<0.05), and decr eases in serum iPTH levels (oral: 391 +/- 48 pg/mL to 230 +/- 55 pg/mL , P<0.05 vs. intravenous: 413 +/- 62 pg/mL to 148 +/- 23 pg/mL, P<0.05 ). These responses to oral or intravenous calcitriol were not statisti cally different. Post-treatment serum calcium (Ca) correlated with ser um iPTH only in patients receiving oral calcitriol, however, suggestin g an additional direct suppressive effect of intravenous calcitriol. T he decision, therefore, to use either formulation of calcitriol would seem to depend on factors in addition to therapeutic efficacy, such as patient compliance and cost.