Generic
Paricalcitol
3 brands available in the market
At a glance
Paricalcitol is a synthetic, biologically active vitamin D2 analog used for the prevention and treatment of secondary hyperparathyroidism associated with Chronic Kidney Disease (CKD) Stages 3, 4, and 5 in patients on dialysis.
Description
Paricalcitol 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.
Indications
- Secondary hyperparathyroidism in CKD Stages 3 and 4
- Secondary hyperparathyroidism in CKD Stage 5 on hemodialysis or peritoneal dialysis
Therapeutic class
Thyroid drugs & hormone
Pharmacological class
Vitamin D Analog
Pharmacology
Paricalcitol is a synthetic, biologically active vitamin D2 analog that selectively activates vitamin D responsive pathways through VDR binding. It reduces parathyroid hormone levels by inhibiting PTH synthesis and secretion.
Mechanism of action
Inhibits parathyroid hormone synthesis and secretion through VDR binding.
Dosage
CKD Stages 3 & 4 (Adults):
- Initial dose (iPTH <500 pg/ml): 1 mcg daily OR 2 mcg three times weekly
- Initial dose (iPTH >500 pg/ml): 2 mcg daily OR 4 mcg three times weekly
- Titration: If iPTH 30-60% decrease: maintain dose; <30% decrease: increase by 1 mcg (daily) or 2 mcg (3x/week); >60% decrease or iPTH <60 pg/ml: decrease by 1 mcg (daily) or 2 mcg (3x/week)
CKD Stage 5 (Adults):
- Initial dose (old formula): baseline iPTH/80; max 5 mcg
- Initial dose (new formula): baseline iPTH/120 (round down)
- Titration: Increase by 1 mcg every 4 weeks or decrease by 1-2 mcg; discontinue if needed
Pediatric Dose (≥10 years): Same as adults for CKD Stages 3, 4, and 5; as directed by physician.
Administration
- May be taken with or without food
- Three times weekly dosing: administer every other day (e.g., Mon, Wed, Fri)
- Take at the same time each day
- If taking with cholestyramine or mineral oil, take at least 1 hour before or 4-6 hours after
Missed dose
If you miss a dose, take it as soon as you remember; skip if it's almost time for next dose; do not double the dose.
Side effects
Side Effects:
- Hypercalcemia
- Hypercalciuria
- Hyperphosphatemia
- Over-suppression of PTH
Precautions & warnings
- Hypercalcemia: Progressive hypercalcemia due to vitamin D overdose may require emergency attention; acute hypercalcemia may exacerbate cardiac arrhythmias and seizures and potentiate digitalis action
- Chronic hypercalcemia can lead to vascular calcification and soft tissue calcification
- Concomitant use with calcium preparations or thiazide diuretics increases hypercalcemia risk
- Digitalis toxicity: Hypercalcemia potentiates digitalis toxicity; caution required
- Prescription-based vitamin D and derivatives should be withheld during treatment
Contraindications
- Hypercalcemia
- Vitamin D toxicity
Drug interactions
- Strong CYP3A4 inhibitors (e.g., ketoconazole): Increase paricalcitol exposure; use with caution
- Cholestyramine, mineral oil: Reduce intestinal absorption; take 1 hour before or 4-6 hours after
Food interactions
Take with food for better absorption.
Use in pregnancy
Use in Pregnancy: Limited data; animal studies showed slightly increased embryofetal loss during organogenesis at 2 and 0.5 times the MRHD. Adverse reproductive outcomes were observed at doses causing maternal toxicity.
Pregnancy Category: C — always consult a doctor before taking during pregnancy.
Use in lactation
Use in Lactation: No information on presence in human milk; present in rat milk. Due to potential serious adverse reactions including hypercalcemia in breastfed infants, breastfeeding is not recommended during treatment.
Pediatric use
Safety and efficacy established in pediatric patients 10-16 years of age for secondary hyperparathyroidism associated with CKD Stages 3, 4, and 5.
Geriatric use
No overall differences in safety and efficacy observed in elderly patients (≥65 years); however, greater sensitivity in some older individuals cannot be ruled out.
Renal / hepatic impairment
Renal Impairment: Indicated for CKD Stages 3, 4, and 5 patients; dose titration and monitoring required.
Hepatic Impairment: Caution in liver disease; dose adjustment may be needed.
Overdose effects
Overdose may cause hypercalcemia, hypercalciuria, hyperphosphatemia, and over-suppression of PTH. Treatment: general supportive measures; induction of emesis or gastric lavage; mineral oil may promote fecal elimination; monitor serum electrolytes and calcium; not significantly removed by dialysis.
Storage conditions
Store below 30°C in a dry place, protected from light; keep out of reach of children.
Chemical structure
Paricalcitol