What is the difference between haemophilia A and B in terms of treatments?
The main difference is that they need injections to replace different clotting factors. In haemophilia A, factor VIII (8) is missing. In haemophilia B, it is factor IX (9) that is missing.
These two clotting factors last for different lengths of time in the blood. So people with severe haemophilia A generally need preventative injections 3 times a week or every other day and those with severe haemophilia B, twice a week.18 This is called prophylaxis (pronounced prof-ill-ax-iss).
There are new treatments for haemophilia A and B that are available. These are known as ‘extended half-life’ factor replacement. They stay in the blood stream for longer, so you don’t have to give yourself the prophylaxis injections so often. For haemophilia A, you may be able to have factor injections twice a week, instead of every other day.27 For haemophilia B, you may be able to have factor injections once a week or once a fortnight instead of twice a week.28,30