[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Vitamins](https://durgical.com/en/pharmacology/classes/vitamins/) › Paricalcitol

# Paricalcitol

## Vitamins?

Vitamins

A synthetic active vitamin D analogue that lowers parathyroid hormone in chronic kidney disease. Calcium must be watched closely.

Updated Nov 1, 2026

## Quick facts

**Group**
[Vitamins](https://durgical.com/en/pharmacology/classes/vitamins/)

**Target**
Vitamin D receptor (nuclear receptor) in the parathyroid glands

**Used for**
Prevention and treatment

**Key effects**
Diarrhoea · Nasopharyngitis · Dizziness

**Monitor**
Serum calcium and phosphorus · Intact PTH

**ATC**
H05BX02

No doses: the clinician sets them by the current guideline.

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Safety Contraindications
- Key interactions
- What is monitored
- Administration and safety
- Pregnancy and breastfeeding
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

◎**Vitamin D receptor (nuclear receptor) in the parathyroid glands**Paricalcitol

ⓘ The figure shows calcitriol, the natural active vitamin D, in the human vitamin D receptor; paricalcitol is an analogue that binds the same pocket.

**Target in 3D:** Vitamin D receptor (nuclear receptor) in the parathyroid glands. PDB structure 1DB1 (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/1DB1) · Drag to rotate · pinch to zoom

Paricalcitol is a synthetic vitamin D2 analogue of calcitriol that does not need activation by the kidney. It binds the vitamin D receptor and selectively activates vitamin D-responsive pathways. In the parathyroid glands it lowers parathyroid hormone synthesis and secretion. It also raises serum calcium and phosphorus, which is why over-suppression and hypercalcaemia are the main risks.

- Paricalcitol binds the vitamin D receptor
- Parathyroid hormone synthesis and secretion fall
- Calcium and phosphorus rise; levels are checked

## Indications

- Prevention and treatment of secondary hyperparathyroidism of chronic kidney disease (stages 3 and 4, and stage 5 on dialysis) [CKD-mineral and bone disorder (renal osteodystrophy) →](https://durgical.com/en/conditions/ckd-mineral-and-bone-disorder/)

## Adverse effects

### Common

- Diarrhoea, nausea, vomiting
- Nasopharyngitis
- Dizziness
- High blood pressure, oedema

### Serious (rare, important)

- Hypercalcaemia, hypercalciuria and hyperphosphataemia
- Over-suppression of PTH and adynamic bone disease
- Digitalis toxicity made worse by high calcium
- Hypersensitivity reactions

## Contraindications

- Hypercalcaemia or vitamin D toxicity

## Key interactions

**Digoxin and other digitalis glycosides**
Hypercalcaemia raises the risk of digitalis toxicity

**Strong CYP3A inhibitors (ketoconazole)**
Higher paricalcitol exposure; used with caution

**Cholestyramine, mineral oil**
Less paricalcitol absorbed; doses are separated

**Other vitamin D products at prescription doses; aluminium-containing compounds**
Added hypercalcaemia risk; aluminium overload and toxicity

## What is monitored

- Serum calcium and phosphorus
- Intact PTH, especially after starting or changing the dose
- Serum creatinine (it can rise and lower estimated GFR)

## Administration and safety

- Oral capsules or IV injection (often during haemodialysis); the dose is adjusted to PTH, calcium and phosphorus.
- Other prescription vitamin D products are withheld during treatment.
- Look-alike risk with calcitriol and other vitamin D analogues; the exact product is checked.

## Pregnancy and breastfeeding

Human data are limited; kidney disease itself carries risks in pregnancy, and use needs a clear benefit.

## Nursing care

- Check calcium, phosphorus and PTH results before giving doses.
- Teach the signs of high calcium: tiredness, confusion, loss of appetite, nausea, constipation, thirst, frequent urination.
- In patients on digoxin, watch for toxicity (nausea, visual changes, arrhythmia).
- Ask about vitamin D supplements, antacids with aluminium and other over-the-counter products.

## Pharmacokinetics

**Absorption**
Well absorbed orally; also given IV during haemodialysis

**Distribution**
Almost entirely bound to plasma proteins

**Metabolism**
Several hepatic and non-hepatic enzymes, including CYP24, CYP3A4 and UGT1A4

**Elimination**
Mainly hepatobiliary, in faeces

## Memory aid

«PARIcalcitol PARks the PARAthyroid»: PTH down, calcium up, so check calcium.

## Test yourself

Think of the answer, then tap the question to see it.

## Why can paricalcitol work in advanced kidney disease when plain vitamin D does not?

It is already an active analogue and does not need renal 1-alpha-hydroxylation.

## What is its main laboratory risk?

Hypercalcaemia (with high phosphorus and PTH over-suppression).

## Which heart drug becomes more dangerous with it?

Digoxin, because high calcium increases digitalis toxicity.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/paricalcitol/)

[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

## Connections

## Related drugs 4

- [Calcitriol](https://durgical.com/en/pharmacology/calcitriol/)
- [Colecalciferol](https://durgical.com/en/pharmacology/colecalciferol/)
- [Cinacalcet](https://durgical.com/en/pharmacology/cinacalcet/)
- [Sevelamer](https://durgical.com/en/pharmacology/sevelamer/)

## Related conditions 1

- [CKD-mineral and bone disorder (renal osteodystrophy)](https://durgical.com/en/conditions/ckd-mineral-and-bone-disorder/)

[← Back to the class: Vitamins](https://durgical.com/en/pharmacology/classes/vitamins/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [DailyMed - PARICALCITOL capsule](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=cd937aab-6ed2-44ef-b91e-82738997ed10) (DailyMed (U.S. National Library of Medicine), 2017); [DailyMed - PARICALCITOL injection](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=8e0b016c-4bda-487e-b525-63abfb772761) (DailyMed (U.S. National Library of Medicine), 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=H05BX02) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); [RCSB PDB - 1DB1: CRYSTAL STRUCTURE OF THE NUCLEAR RECEPTOR FOR VITAMIN D COMPLEXED TO VITAMIN D](https://www.rcsb.org/structure/1DB1) (RCSB Protein Data Bank, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/paricalcitol/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/paricalcitol/