ReFacto® is a medication used to treat hemophilia A, a condition that prevents blood from clotting correctly in affected people. ReFacto® is an antihemophilic protein that acts as a blood clotting agent and can be administered to prevent or treat bleeding episodes. The medication is produced by recombinant DNA technology.
People who are affected by hemophilia A lack a clotting factor called factor VIII, and ReFacto® acts as a substitute for the missing factor. This blood clot medication is a protein, made up of 1,438 amino acids linked together, which is a sequence similar to naturally occurring factor VIII. The medication has the same biological effects in vitro as natural factor VIII.
The medication is used by the body as a cofactor for clotting factor IX. Factor IX and factor VIII, or ReFacto®, convert clotting factor X into an activated form. The activated form of factor X converts prothrombin into thrombin. Thrombin then converts fibrinogen into fibrin. Fibrin forms blood into clots and prevents further bleeding.
The medication is available as a dried, or lyophilized, powder in various strengths. The powder is reconstituted for intravenous injection, or injection into a vein. Injection may be performed by a doctor or nurse, or patients may be trained to self-administer the medication. The frequency of medication can be from every eight hours to 24 hours for one to four days, or as directed by a doctor.
Side effects of using ReFacto® include dizziness, headache, skin rash, runny nose, sore throat, cough, fever or chills, pain or swelling in the joints, nausea and vomiting, an unpleasant taste in the mouth, and irritation of the injection site. More serious side effects include chest pain, bleeding from the site of injection, increased bleeding episodes, and easy bruising. ReFacto® may also cause serious allergic reactions such as hives, trouble breathing, fainting, and swelling of the face, tongue and neck.
ReFacto® is made using a Chinese hamster ovary cell line that has been genetically engineered to produce the active ingredient. The protein is purified from the cell culture using chromatography. This means the medication is not directly purified from human blood, but the cell culture does contain human albumin and recombinant insulin.
Patients taking ReFacto® may produce antibodies to the medication, and the treatment may become less effective in controlling bleeding episodes as a result. If this occurs, medical advice should be sought. People taking ReFacto® may also have to undergo regular blood tests to ensure the medication is working effectively.