This study was carried out to evaluate the efficacy and safety of
doxercalciferol as
therapy for
secondary hyperparathyroidism (SHPT) in patients with
chronic kidney disease (CKD) stage 4 in a prospective clinical trial. A total of 35 CKD-4 patients who had a baseline
parathyroid hormone (iPTH) >150 pg/mL and had not received any
vitamin D analog in the preceding 8 weeks were followed up at intervals of 6 weeks for 18 weeks on oral
therapy with
doxercalciferol. The starting dose was 1.5 μg/day, and the dose was increased in steps of 1 μg/day if iPTH did not decrease by at least 30% on the subsequent visit.
Doxercalciferol was stopped temporarily if low iPTH (<70 pg/mL),
hypercalcemia (>10.7 mg/dL), or severe
hyperphosphatemia (>8.0 mg/dL) occurred, and was restarted at a lower dose on reversal of these abnormalities.
Calcium acetate was the only
phosphate binder used. Mean iPTH decreased by 35.4 ± 4.4% from 381.7 ± 31.3 pg/mL to 237.9 ± 25.7 pg/mL (P < 0.001). The proportion of patients who achieved 30% and 50% suppression of iPTH levels was 83% and 72%, respectively. Mean serum
calcium,
phosphorus, and
calcium-
phosphorus product values did not differ significantly from the baseline values. Four, two, and nine patients developed
hypercalcemia, severe
hyperphosphatemia, and high CaxP (>55), respectively. Almost all patients recovered to an acceptable level within 2 weeks of stopping
doxercalciferol and adjusting the
phosphate binder dose. In all, 21 patients required temporary stoppage of
therapy. Most of them were restarted on
therapy at a reduced dose during the study. It can, therefore, be concluded that
doxercalciferol is effective in controlling SHPT in CKD-4 patients with an acceptable risk of
hyperphosphatemia and
hypercalcemia.