Paricalcitol
Indications
Paricalcitol is used to prevent and treat secondary hyperparathyroidism in people with chronic kidney disease, including those on dialysis. In this condition the parathyroid glands make too much parathyroid hormone (PTH) because the kidneys can no longer activate vitamin D properly, which can weaken bones.
How It Works
Paricalcitol is a man made, active form of vitamin D. It acts on vitamin D receptors in the parathyroid glands and reduces the production of PTH. It does this with less tendency to raise blood calcium and phosphate than some other active vitamin D medicines.
Dosage and Administration
The dose is worked out by your kidney specialist from your PTH, calcium and phosphate blood levels, and is adjusted over time. Capsules are taken by mouth, either once a day or three times a week, with or without food. The injection is given by a doctor or nurse into the dialysis line during haemodialysis. Take exactly as prescribed and attend regular blood tests.
Interactions
- Ketoconazole and other strong CYP3A4 inhibitors may raise paricalcitol levels.
- Digoxin: high calcium levels increase the risk of digoxin toxicity.
- Calcium supplements, Thiazide diuretics and other vitamin D products can raise calcium too much.
- Aluminium containing antacids or phosphate binders should not be used long term with it.
- Cholestyramine and mineral oil may reduce absorption of the capsules.
Contraindications
- Allergy to Paricalcitol.
- High blood calcium (hypercalcaemia) or signs of vitamin D toxicity.
Side Effects
Possible side effects include high blood calcium, high phosphate, headache, nausea, vomiting, diarrhoea, abnormal taste, dizziness, itching and swelling of the hands or feet.
Get urgent medical help if you develop signs of very high calcium (severe tiredness, confusion, constant thirst, passing a lot of urine, vomiting, constipation, muscle weakness, irregular heartbeat) or an allergic reaction with swelling or difficulty breathing.
Pregnancy and Lactation
Use in pregnancy only if the doctor decides the benefit outweighs the risk. It is not known whether it passes into breast milk; discuss with your doctor before breastfeeding.
Precautions and Warnings
- Regular blood tests for calcium, phosphate and PTH are needed, especially when starting or changing the dose.
- Follow the diet advice on phosphate and calcium from your kidney team.
- Do not take extra vitamin D or calcium unless your doctor tells you to.
- Over suppression of PTH can lead to bone problems; doses are adjusted to avoid this.
Overdose
Too much can cause high calcium, with symptoms such as weakness, confusion, nausea, vomiting, thirst and heart rhythm problems. Seek medical help straight away.
Therapeutic Class
Vitamin D analogue (selective vitamin D receptor activator).
Storage
Store below 30°C in a dry place, away from light and out of the reach of children. Injections are stored as directed on the pack.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.
All brands of Paricalcitol