General Information

Zemplar (paricalcitol injection) is a vitamin D analog.

Zemplar is specifically indicated for:

adults and pediatric patients 10 years of age and older for the prevention and treatment of secondary hyperparathyroidism associated with Chronic Kidney Disease (CKD) Stages 3 and 4.

adults and pediatric patients 10 years of age and older for the prevention and treatment of secondary hyperparathyroidism associated with CKD Stage 5 in patients on hemodialysis (HD) or peritoneal dialysis

Zemplar is supplied as capsules for oral administration. The recommended dosing is as follows:

Chronic Kidney Disease Stages 3 and 4 in Adults

Administer Zemplar capsules orally once daily or three times a week. When dosing three times weekly, do not administer more frequently than every other day.

Initial Dose:

Baseline iPTH Level

Daily Dose

Three Times a Week Dose (To be administered not more often than every other day)

Less than or equal to 500 pg/mL

1 mcg

2 mcg

More than 500 pg/mL

2 mcg

4 mcg

Dose Titration:

Dose Adjustment at 2 to 4 Week Intervals

iPTH Level Relative to Baseline

Zemplar Capsule Dose

Daily Dosage

Three Times a Week Dosage (to be administered not more often than every other day)

The same, increased or decreased by less than 30%

Increase dose by

1 mcg

2 mcg

Decreased by more than or equal to 30% and less than or equal to 60%

Maintain dose

Decreased by more than 60% or iPTH less than 60 pg/mL

Decrease dose by

1 mcg

2 mcg

If a patient is taking the lowest dose, 1 mcg, on the daily regimen and a dose reduction is needed, the dose can be decreased to 1 mcg three times a week. If a further dose reduction is required, the drug should be withheld as needed and restarted at a lower dosing frequency.

Chronic Kidney Disease Stage 5 in Adults

Initial Dose:

Administer the dose of Zemplar capsules orally three times a week, no more frequently than every other day based upon the following formula: Dose (micrograms) = baseline iPTH (pg/mL) divided by 80 Treat patients only after their baseline serum calcium has been adjusted to 9.5 mg/dL or lower to minimize the risk of hypercalcemia

Dose Titration:

Individualize the dose of Zemplar based on iPTH, serum calcium and phosphorus levels. Titrate Zemplar dose based on the following formula: Dose (micrograms) = most recent iPTH level (pg/ml) divided by 80 If serum calcium is elevated, the dose should be decreased by 2 to 4 micrograms. As iPTH approaches the target range, small, individualized dose adjustments may be necessary in order to achieve a stable iPTH. In situations where monitoring of iPTH, Ca or P occurs less frequently than once per week, a more modest initial and dose titration ratio (e.g., iPTH divided by 100) may be warranted.

Pediatric Patients (Ages 10 to 16 Years)

CKD Stages 3 and 4

Initial Dose
- Administer Zemplar 1 mcg capsule orally three times a week, no more frequently than every other day.
Dose Titration
- Individualize and titrate Zemplar dose based on iPTH, serum calcium and phosphorus levels to maintain an iPTH level within target range. Every 4 weeks, each administered Zemplar dose may be increased in 1 mcg increments, maintaining the three times per week regimen (e.g., increase from 1 mcg three times per week to 2 mcg three times per week). At any time, each administered dose may be decreased by 1 mcg. Zemplar may be stopped if the patient requires reduction while receiving 1 mcg three times per week, resuming when appropriate.

CKD Stage 5

Initial Dose
- Administer the dose of Zemplar capsules orally three times a week, no more frequently than every other day based upon the following formula: Dose* (micrograms) = baseline iPTH (pg/mL) divided by 120 * Round down to the nearest whole number
Dose Titration
- Subsequent dosing should be individualized and based on iPTH, serum calcium and phosphorus levels to maintain an iPTH level within target range. Every 4 weeks, each administered Zemplar dose may be increased in 1 mcg increments, maintaining the three times per week regimen (e.g., increase from 1 mcg three times per week to 2 mcg three times per week). At any time, each administered dose may be decreased by 2 mcg. Zemplar may be stopped if the patient requires reduction while receiving 2 mcg three times per week or 1 mcg three times per week, resuming when appropriate

Mechanism of Action

Zemplar (paricalcitol injection) is a synthetic, biologically active vitamin D2 analog of calcitriol. Preclinical and in vitro studies have demonstrated that paricalcitol's biological actions are mediated through binding of the VDR, which results in the selective activation of vitamin D responsive pathways. Vitamin D and paricalcitol have been shown to reduce parathyroid hormone levels by inhibiting PTH synthesis and secretion.