Viva-D Injection

Indications

Alfacalcidol is an active form of vitamin D used to treat conditions where the body cannot activate vitamin D properly, mainly due to kidney disease. These include bone disease caused by chronic kidney failure (renal osteodystrophy), raised parathyroid hormone (secondary hyperparathyroidism), low parathyroid hormone (hypoparathyroidism), certain types of rickets and osteomalacia (soft bones), and low calcium in newborns. It is available as capsules, oral drops and an injection.

How It Works

Vitamin D must be activated in the liver and kidneys before it can work. Alfacalcidol (1-alpha-hydroxyvitamin D3) only needs the liver step, so it works even when the kidneys are damaged. In the liver it becomes calcitriol, the active hormone, which increases calcium and phosphate absorption from the gut, helps build bone and lowers excess parathyroid hormone.

Dosage and Administration

The dose is as prescribed and depends on the condition, blood calcium and phosphate levels, and age or body weight. It is usually started at a low dose and adjusted every few weeks according to blood tests. Capsules and drops are taken by mouth, usually once a day. The injection is given into a vein by a doctor or nurse, often during dialysis. Do not change the dose yourself.

Interactions

• Other vitamin D products and calcium supplements: increase the risk of high calcium; use only as advised.
• Thiazide diuretics such as Hydrochlorothiazide: may raise calcium further.
• Digoxin: high calcium can make heart rhythm problems more likely.
• Antacids or laxatives containing magnesium: risk of high magnesium in kidney disease.
• Phenytoin, Phenobarbital, Carbamazepine, Cholestyramine and mineral oils: may reduce its effect.

Contraindications

Do not use Alfacalcidol if you have high blood calcium (hypercalcaemia), signs of vitamin D toxicity, or an allergy to it or any ingredient.

Side Effects

The main side effects come from too much calcium or phosphate in the blood: nausea, vomiting, constipation, loss of appetite, thirst, passing more urine, tiredness, weakness, headache and confusion. Itching, rash and kidney stones can also occur. The injection may cause pain at the injection site.

Get urgent medical help if you have severe vomiting, extreme thirst, confusion or drowsiness, an irregular heartbeat, severe stomach or back pain, or signs of an allergic reaction such as swelling of the face or difficulty breathing.

Pregnancy and Lactation

Use in pregnancy only if your doctor feels it is needed, as high calcium can harm the baby. It passes into breast milk; if used while breastfeeding, the baby's calcium may need checking. Follow your doctor's advice.

Precautions and Warnings

Regular blood tests for calcium, phosphate, parathyroid hormone and kidney function are essential, especially at the start and after dose changes. Follow any diet advice on calcium and phosphate, and take phosphate binders if prescribed. Drink enough fluids. Tell your doctor about any other vitamin or mineral supplements.

Overdose

An overdose can cause dangerously high calcium, with vomiting, confusion, heart rhythm problems and kidney damage. Stop the medicine and seek medical help straight away.

Therapeutic Class

Vitamin D analogue (active vitamin D).

Storage

Capsules and drops: store below 30°C in a dry place, away from light. Injection: store as directed on the pack, usually in a refrigerator at 2 to 8°C, do not freeze. Keep out of the reach of children.