Intravenous Paricalcitol for Treatment of Secondary Hyperparathyroidism in Children on Hemodialysis

Background

Secondary hyperparathyroidism is a common complication in children receiving hemodialysis. Active vitamin D is an effective therapy, but its use is often limited by hypercalcemia and increased calcium × phosphorus (Ca × P) product. Paricalcitol, a selective vitamin D receptor activator, causes less sustained hypercalcemia and increase in Ca × P product than calcitriol and has been used effectively in adult hemodialysis patients.

Study Design

Double blind, placebo-controlled.

Setting & Participants

Hemodialysis units and pediatric subjects receiving hemodialysis.

Intervention

After a washout period of 2 to 6 weeks, 29 subjects aged 5 to 19 years received either paricalcitol or placebo for up to 12 weeks (0.04 μg/kg if initial intact parathyroid hormone [iPTH] level < 500 pg/mL [ng/L]; 0.08 μg/kg if initial iPTH level > 500 pg/mL [ng/L]). The dose was increased by 0.04 μg/kg every 2 weeks until there was a 30% decrease in iPTH level from baseline or calcium level greater than 11 mg/dL (>2.74 mmol/L) or Ca × P product greater than 75 mg²/dL² (>6.04 mmol²/L²).

Outcomes & Measurements

Two consecutive 30% decreases from baseline in iPTH levels and safety of paricalcitol, including hypercalcemia and increase in Ca × P product.

Results

60% of the paricalcitol group had 2 consecutive 30% decreases from baseline iPTH levels compared with 21% in the placebo group (P = 0.06). The paricalcitol group had a mean decrease in iPTH level of 164 pg/mL (ng/L), whereas the placebo group had a mean increase of 238 pg/mL (ng/L; P = 0.03). There was no difference from baseline to final visit in calcium, phosphorus, or Ca × P product values in either group.

Limitations

Low power to detect differences in safety between groups and a short-term study.

Conclusion

Paricalcitol decreased iPTH levels in children receiving hemodialysis with no significant changes in serum calcium, phosphorus, or Ca × P product values during the course of the study.

Index Words: Paricalcitol, secondary hyperparathyroidism, hemodialysis, end-stage renal disease, children