Recombinant activated factor VII, used to control bleeding
Factor VIIa
A laboratory-made activated clotting factor given by injection to control bleeding, especially when inhibitors are present.
What is Factor VIIa?
Factor VIIa is a specialist, laboratory-made (recombinant) clotting factor used to control bleeding, particularly in people with haemophilia who have developed antibodies, called inhibitors, that stop standard clotting factors working. It is given by injection into a vein. Its most important risk is that, because it boosts clotting, it can cause unwanted clots, including heart attacks, strokes and clots in the veins, so it is used carefully under specialist supervision. It is a specialist treatment used by haemophilia and other expert teams in specific situations.
Education and reference only. This is a plain-language guide to Factor VIIa — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Factor VIIa is an activated form of a clotting protein, made in the laboratory rather than from human blood (recombinant). It is used to control bleeding in particular situations, most notably in people with haemophilia who have developed inhibitors, antibodies that stop the usual factor VIII or factor IX treatments from working. By boosting clotting through a different route, it can help stop bleeding when standard replacement does not work. It is given by injection into a vein and is a specialist treatment used by haemophilia and other expert teams, who weigh its benefits against the risk of unwanted clots.
How it works
Clotting depends on a chain of proteins; factor VIIa acts near the start of this chain and helps drive clot formation, especially at the site of an injury. Because it works through a route that does not rely on factor VIII or factor IX, it can help control bleeding even in people whose inhibitors block those factors. By promoting clotting where bleeding is happening, it helps stop the bleed. The flip side is that, by boosting clotting, it can also encourage clots to form where they are not wanted, which is the main reason it is used carefully and under specialist supervision.
Company & origin
Originated / developed by: Specialist manufacturer.
A specialist laboratory-made medicine used in the UK to control bleeding, especially in haemophilia where antibodies (inhibitors) stop standard clotting factors working.
Practical use
How to take Factor VIIa
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given by injection into a vein, usually under or arranged by a specialist team, to control bleeding.
- It is often given as repeated doses while a bleed is being brought under control.
- Seek urgent help for signs of a clot, such as chest pain, breathlessness, leg swelling or stroke-like symptoms.
- Tell your team about any history of heart problems, strokes or clots, as these affect whether it is suitable.
- It is used in specific situations, such as haemophilia with inhibitors, as decided by the specialist team.
Weighing it up
Advantages & disadvantages of Factor VIIa
Advantages
- Can control bleeding even when inhibitors stop standard factor VIII or factor IX treatments from working.
- Works through a different clotting route, offering an option when usual replacement fails.
- Being laboratory-made, it does not carry the risks linked to products made from human plasma.
Disadvantages
- Can cause serious unwanted clots, including heart attacks, strokes and clots in the veins or lungs.
- Must be used carefully under specialist supervision, weighing benefit against clot risk.
- Given by injection into a vein, often as repeated doses, and reserved for specific situations.
Practical use
Good to know
The dominant concern with factor VIIa is that, because it boosts the blood's tendency to clot, it can cause unwanted and serious clots, including heart attacks, strokes and clots in the veins or lungs. This risk is taken very seriously, especially in older people or those with heart or circulation problems, so it is used under specialist supervision and only when the benefit of controlling bleeding outweighs this risk. It is mainly used in haemophilia when inhibitors stop the usual factor treatments from working, as well as in some other specialist bleeding situations. It is given by injection into a vein, often as repeated doses while bleeding is being controlled. The specialist team watches closely for both whether the bleeding is settling and any signs of a clot, such as chest pain, breathlessness, leg swelling or stroke-like symptoms, which need urgent attention.
Who should not take it / use with caution
- It is used with great caution, or avoided, in people at high risk of clots, such as those with recent heart attacks, strokes or clots.
- People who have had a serious allergic reaction to it should not use it.
- It should only be used under specialist supervision, with the risk of clots carefully weighed.
Monitoring
- Watching closely for signs of unwanted clots, such as chest pain, breathlessness or stroke-like symptoms.
- Reviewing how well the bleeding is being controlled.
- Watching for allergic reactions during and after treatment.
Side effects
- Unwanted clots, including heart attacks, strokes and clots in the veins or lungs, which is the main concern.
- Allergic-type reactions, which can rarely be serious.
- Fever or reactions where the injection is given.
Key interactions
- It is used with extra care alongside other medicines that affect clotting, which the team reviews.
- Tell your team about all your medicines and any history of clots, heart attacks or strokes.
- Certain other clotting products are used with caution together, under specialist guidance.
Available as: A powder made up into a solution for injection into a vein.
Answers
Factor VIIa: frequently asked questions
What is factor VIIa used for?
It is a specialist medicine used to control bleeding, especially in people with haemophilia who have inhibitors that stop standard factor treatments from working.
Why does it carry a clot risk?
Because it boosts the blood's ability to clot, it can also cause clots where they are not wanted, including heart attacks, strokes and clots in the veins, so it is used carefully.
Is it made from human blood?
No. It is recombinant, meaning it is made in the laboratory, so it does not carry the risks linked to products made from human plasma.
When is it used instead of the usual factors?
It is mainly used when inhibitors block the usual factor VIII or factor IX treatments, as well as in some other specialist bleeding situations.
What signs of a clot should I watch for?
Seek urgent help for chest pain, breathlessness, swelling or pain in a leg, or stroke-like symptoms such as weakness or trouble speaking.
Authoritative sources
- BNF
- NICE CKS
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