Long-term therapy with paricalcitol for secondary hyperparathyroidism in hemodialysis patients.

PURPOSE: The efficacy of the vitamin D analog paricalcitol has mainly been shown in short-term studies. There are limited data regarding long-term treatment with this agent. This purpose of this study was to determine long-term effects of paricalcitol therapy on parathyroid hormone (PTH) suppression and serum levels of calcium, phosphorus and calcium-phosphorus product (Ca x P).

PATIENTS AND

METHODS

Patients who received paricalcitol for > or = 3 months had the following data collected: demographics, drug dosage, serum PTH, corrected serum calcium concentration, serum phosphorus concentrations and serum Ca x P values.

RESULTS

Sixteen patients received paricalcitol for a mean of 18 months. The mean +/- SD dose of paricalcitol was 0.13 +/- 0.12 mcg/kg. The mean +/- SD pre-paricalcitol serum PTH concentration was 705 +/- 423 pg/mL. PTH concentration did not change significantly over the duration of treatment (mean +/- SD: 821 +/- 480 pg/mL). The number of patients who had at least one corrected serum calcium concentration > or = 11.5 mg/dL, one serum phosphorus concentration > or = 6.5 mg/dL, or one Ca x P level > or = 70 were 75%, 94% and 82%, respectively. Hypercalcemia and elevated Ca x P value resulted in a mean of 17% of doses being withheld during therapy.

CONCLUSION

During the study, PTH was not adequately suppressed by paricalcitol. This was primarily attributed to withholding paricalcitol doses due to elevated serum calcium and Ca x P levels.