Dosing Zemplar (Paricalcitol) Capsules for a Patient with Secondary Hyperparathyroidism in Chronic Kidney Disease

 

Biological marker: intact parathyroid hormone (PTH) in ng/L (pg/mL)

 

 

Baseline PTH level	Daily Dosage in microgram	Dosage 3 Times per Week
< 500 ng/L	1 µg/day	2 µg three times a week
>= 500 ng/L	2 µg/day	4 µg three times a week

 

The 3 times per week dosage protocol is given every other day (for example, Monday, Wednesday and Friday).

 

Parameters:

(1) previous intact PTH level

(2) current intact PTH level

 

ratio of current to previous intact PTH level =

= (current intact PTH) / (previous intact PTH)

 

percent decrease in intact PTH =

= 100% - ((ratio of current to previous intact PTH) * 100%)

 

Ratio of Current to Previous Intact PTH	Daily Dosage in microgram	3 Times per Week Dosage
>= 1.0	increase dose 1 µg/day	increase each dose 2 µg
0.71 - 0.99	increase dose 1 µg/day	increase each dose 2 µg
0.40 - 0.70	no change	no change
< 0.40 or intact PTH < 60 ng/L	decrease dose 1 µg/day	decrease each dose 2 µg

 

If the patient requires a dosage reduction and is already at the lowest dose:

(1) if the patient is taking the daily regimen, then switch to the 3 time per week protocol at 1 µg per dose.

(2) consider withholding one or more doses.

(3) if the patient is taking a calcium-based phosphate binder, then consider (a) reducing the binder dose, or (b) withholding a binder dose, or (c) switching to a non-calcium binder

 

If the patient has hypercalcemia or an elevated (calcium * phosphate) product, then the dose of paricalcitol should be withheld or reduced until the abnormal value returns to normal.

 

The dose of paricalcitol should be adjusted when potent P450 3A inhibitors are administered or withdrawn.