To treat with factor concentrate, it must be injected with a needle into a vein. This is called infusing factor. The steps to prepare and infuse factor are given in another section. This section describes when to take factor.
There are a number of approaches to treating a bleeding disorder. One is called on-demand treatment. In this approach, the person with the bleeding disorder takes factor after bleeding has begun. He may need to infuse factor several times until the bleeding stops.
In the prophylactic approach, the person with a bleeding disorder infuses to keep his factor level high enough to prevent a bleed. This is considered the optimal treatment for young children with severe hemophilia A and hemophilia B. Factor is given two or three times a week to keep the level in the blood high enough to prevent bleeds. In this approach, a lot of money is spent on factor but you save money in the long run. This is because you spend less money treating the complications of bleeds.
A person with a bleeding disorder may use the prophylactic approach when he knows he is going to do an activity likely to cause bleeding. He will take the factor before he does the activity so he doesn’t have a bleed. He might also do this before the dentist works on his teeth. Sometimes the hemophilia doctor prescribes taking factor before or after surgery to prevent bleeding.
Factor may be given to stop a pattern of bleeds. A person with hemophilia can have repeated bleeding in the same joint over time. The joint in which this happens is called a "target joint." To treat a target joint, his doctor may have him take factor every two to four days for a few weeks or longer. The factor level in the person’s blood is raised high enough to prevent bleeding. The person with hemophilia can exercise to strengthen the muscles and joint. It is hoped that with stronger muscles the bleeding will not start again when treatments are stopped.
How long factor works in your body
Clotting factor that has been infused does not stay in the body but is used up. The rate at which it is used up is called its “half-life”. The half-life of factor VIII is 8 to 12 hours. This means that the amount of factor VIII working in the body drops by half 8 to 12 hours after taking it.
For example: Suppose a person with hemophilia A takes factor at 8:00 a.m. on Sunday to raise his level to 40%. By 8:00 p.m. on Sunday, 12 hours later, his level will have dropped by half (to 20%). Twelve hours later, or by 8:00 a.m. on Monday, his factor activity level will have dropped by half again and will be at 10%. At this point, he may need to take factor again if he is still bleeding. By 8:00 p.m. Monday, his factor level will have dropped by half again. If he did not re-treat Monday morning, his level will now be 5% and he will need to re-infuse if he is still bleeding.
Factor IX lasts longer in the body than factor VIII. The half-life is 18 to 24 hours. This means that the amount of factor IX working in the body has dropped by half 18 to 24 hours after taking it.
For example: Suppose a person with hemophilia B raises his factor level to 40% at 8 a.m. on Sunday. By the next morning, 18 to 24 hours later, his factor level will have dropped by half to 20%. It will be early Tuesday morning before his factor level will drop by half again to 10%.
The time of day to take factor
You should never delay taking factor if you think you are having a bleed. By treating right away, you can reduce the number of treatments needed to stop the bleeding. This saves money and hassles. It also lowers the chances of having permanent damage.
Sometimes hemophilia doctors want you to take factor regularly for a period of time to prevent bleeds. The best time for this prophylactic or preventive treatment is in the morning. By taking factor in the morning, you can have your highest factor level during your most active time of the day. You will have the most protection at the time you are most likely to bleed.
If you take factor at night, your factor level will be highest when you are asleep. It will have dropped by half the next morning when you really need the protection.
How many doses to take
Usually one dose of factor is all that is needed to stop a mild to moderate bleed. If the symptoms get worse or last longer than you expect, you may still be bleeding. Call your HTC for advice.
Different types of bleeds need a different number of doses. Your HTC can provide you with treatment plans for the various types of bleeds.
You may need to take more doses of factor if:
You did not treat early enough.
You did not use a high enough dose of factor.
You have been too active on a joint after a bleed.
You have a very bad or difficult bleed and need to be sure it doesn’t start again. (Since there may be a medical reason for the problem, you may need to talk to your doctor.)