Doxerol

Indications

Doxercalciferol is a man-made form of vitamin D. It is used to treat secondary hyperparathyroidism (overactive parathyroid glands caused by kidney disease) in adults with chronic kidney disease, including those on dialysis. Untreated, high parathyroid hormone (PTH) levels can weaken the bones.

How It Works

Doxercalciferol is a vitamin D2 analogue that is activated in the liver into an active form of vitamin D. This active form acts on the parathyroid glands to lower the production of PTH and helps the gut absorb calcium. Because damaged kidneys cannot fully activate ordinary vitamin D, this medicine bypasses the kidney step.

Dosage and Administration

It is taken as capsules by mouth or given as an injection into a vein at the end of a dialysis session by a nurse. The starting dose and later changes are set by the doctor according to blood PTH, calcium and phosphate levels, so take it exactly as prescribed. Do not take other vitamin D products unless your doctor agrees.

Interactions

• Digoxin: high calcium increases the risk of heart rhythm problems
• Other vitamin D products and calcium supplements: risk of high calcium
• Magnesium-containing antacids or laxatives: risk of high magnesium in kidney disease
• Ketoconazole and similar enzyme blockers, or enzyme inducers such as Phenytoin or Rifampicin, may change its activation
• Cholestyramine and mineral oil can reduce absorption of the capsules

Contraindications

• High blood calcium (hypercalcaemia)
• Vitamin D toxicity
• Allergy to Doxercalciferol or any ingredient

Side Effects

Common effects include swelling of the hands or feet, headache, nausea, vomiting, itching, dizziness, shortness of breath and feeling unwell. The main risk is high blood calcium, which can cause tiredness, weakness, confusion, constipation, loss of appetite, increased thirst and passing more urine.

Get urgent medical help for signs of a serious allergic reaction, severe confusion, an irregular heartbeat, severe vomiting or fainting.

Pregnancy and Lactation

There is limited information in pregnancy, so it is used only if the doctor decides it is clearly needed. 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. Too much suppression of PTH can lead to bone problems. Follow the diet and phosphate binder advice from your kidney team. Use with care in liver disease.

Overdose

Overdose causes high blood calcium with weakness, vomiting, confusion and heart rhythm changes. Stop the medicine and seek medical help; treatment includes stopping calcium and vitamin D, and adjusting dialysis.

Therapeutic Class

Vitamin D analogue; anti-parathyroid agent.

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.