Factor Replacement Therapy
All replacement clotting factor treatments are infused. This means they are injected from a needle placed into the vein (called intravenously). This process takes time; it isn’t like getting a quick shot. Patients who are first diagnosed with hemophilia and need immediate treatment will initially be treated at the HTC, the doctor’s office, or the emergency department. Later, patients (or caregivers) will learn to infuse the factor at home (called home therapy).
Various devices (called ports, catheters, or PICC lines) may be used to make it easier to administer clotting factor products into the bloodstream. Some of these may be surgically inserted under the skin in the chest area. Your doctor and you will decide which type of device is right for you, or your child.
Clotting factor (called factor) is a dried powder form of the missing clotting factor; it is mixed with water to become a liquid again before it is administered. Some clotting factor products, called plasma-derived factor, are made from donated human blood plasma. Others, called recombinant clotting factor, are genetically engineered in a laboratory and do not use human blood proteins.
The National Hemophilia Foundation's (NHF) Medical and Scientific Advisory Council (MASAC) encourages the use of recombinant factor products for young children. Because recombinant products do not contain human blood, they cannot transmit harmful viruses such as hepatitis. That said, the clotting factors that contain human blood are safer today because of better screening of blood donors and better methods to destroy any blood-borne viruses that could be present in the donated blood. Discuss with your doctor or the HTC staff the benefits and challenges of each treatment plan so that you can determine which type of clotting factor product is right for your specific needs. The dosage may vary depending on the severity of the bleeding disorder, weight, and type of bleed.
Clotting Factor Amounts
The amount of clotting factor (called factor) needed to treat a particular type of bleeding episode will vary:
- According to the location of the bleeding site
- If it is a site of repeated bleeding (for example, if it is at a target joint)
- If the bleeding could cause damage to the brain or other vital organs
Sometimes another dose is needed several hours after the first dose is given to stop the bleeding. The amount of factor depends on several other things as well, including:
- The number of units in the bottle (called a vial), which can vary depending on the type of product. As weight increases, dosages will tend to get larger. Your treatment team will help you learn how much factor you need and when to treat a potential bleeding episode
Clotting Factor Half-Life
When clotting factor (called factor) is given, the level of clotting factor in the blood rises; but this rise lasts only for a certain number of hours (called half-life). Half-life is the amount of time it takes the body to “use up” half of the clotting factor level that is circulating in the body. If some time has passed since giving your child treatment and he or she still has pain, stiffness, or other signs of bleeding, another factor treatment may be needed. Sometimes another treatment is recommended to be sure that a stable clot has formed and the bleeding does not start again once the level of clotting factor drops after treatment.
Your HTC can provide exact instructions on when to repeat treatment.
Having factor available is important because you never know when a bleed might occur and prompt treatment is critical; you should always have clotting factor (called factor) with you. This includes when you’re home, in the car, on vacation, and even when you go to the emergency room.
The Centers for Disease Control and Prevention’s (CDC) rule of thumb is to always have at home at least enough clotting factor to give 2 high-dose treatments—that's enough to treat a major traumatic event, such as a head bleed.
Talk to your HTC about the factor and supplies you need, their storage and disposal, and how to order supplies.
Making Your Clotting Factor Work for You: Understanding Half-Life in Your Life
Sometimes other agents are given to individuals with hemophilia. Usually these treatments are given orally or by a nasal spray. Some of them are available in forms that are given by infusion.
- Desmopressin acetate (DDAVP): a synthetic form of a naturally occurring hormone. It helps release von Willebrand factor and factor VIII (8) from where they are stored in the body tissues. For people with mild, and some cases, moderate hemophilia or von Willebrand disease, it can help increase their own factor VIII (8) levels so that they do not have to use a clotting factor. This medicine can be administered intravenously or by nasal spray
- Epsilon amino caproic acid and tranexamic acid: chemicals that prevent clots from breaking down, allowing a firmer clot to form. It is often used for bleeding in the mouth (for example, after a tooth has been removed), because it blocks an enzyme in the saliva that causes clots to come apart. Amino caproic acid can be given intravenously or taken by mouth (as a pill or a liquid). Tranexamic acid can be given by injection or by mouth (as a pill)