Paricalcitol Versus Calcitriol for Efficacy and Safety in Stage 3/4 Chronic Kidney Disease (CKD) With Secondary Hyperparathyroidism (SHPT)

Inclusion Criteria

1. Age >18; Able to give informed consent

2. Chronic kidney disease, and estimated GFR 15 to 60 ml/min using the abbreviated MDRD equation

3. intact PTH (iPTH) >120 pg/ml at baseline

4. albumin corrected calcium > 8.5 mg/dL to < 10.0 mg/dL at baseline

5. Phosphorus < 4.6 mg/dL at baseline

6. If on a phosphorus binder; no change in dose within the 4 weeks prior to screening

Exclusion Criteria

1. Receiving any active form of vitamin D within 4 weeks prior to screening (calcitriol, doxercalciferol; paricalcitol; alfacalcidol)

2. Receiving >50,000 IU per month of ergocalciferol or > 1000 IU of cholecalciferol per day within the previous 30 days.

3. history of primary HPT

4. On prednisone > 30 days within the previous 6 months

5. receiving bisphosphonates or calcitonin within the previous 12 months

6. Non-elective hospitalization within the previous 30 days.

7. Expected to initiate dialysis or receive a kidney transplant within the next 6 mo.

8. History of renal or other organ transplant

9. History of parathyroidectomy or previous diagnosis of primary hyperparathyroidism

10. Receiving cinacalcet within 4 weeks prior to screening.

11. An active drug/alcohol dependence or abuse history

12. History of non-compliance with visits or medications that preclude study compliance in the opinion of the investigator

13. Pregnant, or able to become pregnant and unwilling to use a birth control method considered reliable by the principal investigator