Indications
Human coagulation factor VIII is a clotting protein purified from donated human plasma. It is used to treat and prevent bleeding in people with haemophilia A, an inherited condition in which the blood lacks enough factor VIII and does not clot properly. It is used for bleeding episodes, before and after surgery, and as regular preventive treatment (prophylaxis) to reduce bleeds into joints and muscles. Some plasma-derived factor VIII products also contain von Willebrand factor and may be used in von Willebrand disease when the specialist chooses so.
How It Works
Factor VIII is a natural part of the body’s clotting chain. In haemophilia A it is missing or low, so bleeding lasts longer. The injected factor VIII temporarily replaces the missing protein, 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 dose and frequency are worked out by the specialist from body weight, the factor VIII 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 medicines that affect platelet function, such as Aspirin and other NSAIDs, unless the specialist advises otherwise.
Contraindications
- Known allergy to factor VIII or any ingredient of the product.
Side Effects
Possible effects include allergic reactions (rash, hives, flushing, tightness in the chest), fever, headache and reactions at the injection site. Some patients develop inhibitors, antibodies that make the treatment less effective, especially in the first treatment days. Because it is made from human plasma, a very small risk of passing on infections cannot be fully excluded, although donors are screened and the product is virus-inactivated.
Get urgent medical help if you develop hives, swelling of the face or throat, wheezing, difficulty breathing, dizziness or fainting, or if bleeding does not stop or keeps coming back despite the usual dose, which may mean an inhibitor has developed.
Pregnancy and Lactation
Haemophilia A 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
Regular checks for inhibitors are done, especially in previously untreated patients. Vaccination against hepatitis A and B is usually recommended. Keep a record of each dose and batch number. Contact the haemophilia centre if bleeding is not controlled.
Overdose
No symptoms of overdose have been reported. Contact your haemophilia centre if more than the prescribed dose is given.
Therapeutic Class
Haemostatic agent; plasma-derived coagulation factor VIII.
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.