Indications
Coagulation factor IX is a clotting protein used to treat and prevent bleeding in people with haemophilia B (also called Christmas disease), an inherited condition in which the blood lacks enough factor IX. It is used for bleeding episodes, to cover surgery and dental procedures, and as regular preventive treatment to reduce bleeds into joints and muscles. Products may be purified from donated human plasma or made by recombinant technology.
How It Works
Factor IX is a natural part of the body’s clotting chain. In haemophilia B it is missing or low, so bleeding lasts longer. The injected factor IX temporarily replaces it, allowing the clotting chain to work and a stable clot to form.
Dosage and Administration
It is given as a slow injection into a vein by a doctor or nurse, or at home by a patient or carer trained by a haemophilia centre. The specialist sets the dose and how often it is given based on body weight, the factor IX level needed, the type and site of bleeding and the response. The powder is dissolved in the supplied solvent just before use.
Interactions
No significant interactions with other medicines are known. Do not mix it with other medicines in the same syringe. Avoid Aspirin and other NSAIDs that affect platelets unless the specialist advises otherwise.
Contraindications
- Known allergy to factor IX, any ingredient of the product, or (for some products) hamster or mouse proteins or heparin.
Side Effects
Possible effects include allergic reactions (rash, hives, flushing, chest tightness), headache, fever, nausea and injection site reactions. Some patients develop inhibitors (antibodies that reduce the effect). In haemophilia B, inhibitors can be linked with severe allergic reactions and, in some patients on long courses, kidney problems (nephrotic syndrome). High doses carry a small risk of blood clots. For plasma-derived products, a very small risk of infection transmission cannot be fully excluded.
Get urgent medical help for hives, swelling of the face or throat, wheezing, difficulty breathing or fainting, chest pain, painful swelling of a leg, sudden breathlessness, swelling of the body with foamy urine, or if bleeding does not stop despite the usual dose.
Pregnancy and Lactation
Haemophilia B is rare in women, so experience in pregnancy and breastfeeding is limited. It is used only if the specialist decides it is clearly needed.
Precautions and Warnings
The first doses are usually given under medical supervision because of the risk of allergic reactions. Inhibitor tests are done regularly. People with liver disease, recent surgery or a risk of clots need close monitoring. Vaccination against hepatitis A and B is usually recommended for users of plasma-derived products. Keep a record of each dose and batch number.
Overdose
No specific symptoms of overdose are known, but very high doses may increase clot risk. Contact your haemophilia centre if too much has been given.
Therapeutic Class
Haemostatic agent; coagulation factor IX.
Storage
Store as directed on the pack, usually at 2 to 8°C (some products may be kept at room temperature for a limited time). Do not freeze. Keep in the carton to protect from light. Use the mixed solution promptly. Keep out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.