(AHF, Factor VIII)
AHF, Factor VIII
Pregnancy Category: C
Antihemophilic Factor (Porcine) Hyate:C
Antihemophilic factor either is isolated from pooled normal human blood or is derived from monoclonal antibodies. The potency and purity of preparation vary but each lot is standardized. Details on the package should be noted. Plasma protein (factor VIII) accelerates abnormally slow transformation of prothrombin to thrombin.
1/2: 9-15 hr. One AHF unit is the activity found in 1 mL of normal pooled human plasma.
Control of bleeding in clients suffering from hemophilia A (factor VIII deficiency and acquired factor VIII inhibitors). These products temporarily replace the missing clotting factor in order to correct or prevent bleeding episodes or to perform surgery. AHF is safe and effective for use in children of all ages, including neonates. Treat spontaneous or trauma-induced bleeding episodes in severe von Willebrand's disease and in mild or moderate von Willebrand's disease where use of desmopressin is inadequate.
Use of monoclonal antibody-derived AHF in clients hypersensitive to bovine, hamster, or mouse protein.
Since AHF is prepared from human plasma, there is a risk of transmitting hepatitis or AIDS. However, the products are carefully prepared and tested.
CNS: Headache, somnolence, lethargy, fatigue, dizziness.
CV: Increased bleeding tendency, flushing, slight hypotension, acute hemolytic anemia, hyperfibrinogenemia.
Allergic: Nausea, fever, hives, chills, urticaria, wheezing, hypotension, chest tightness, stinging at infusion site, hypotension,
Miscellaneous: Sore throat, cold feet, taste perversion, nonspecific rash.
Antibodies may form to the mouse protein found in AHF derived from monoclonal antibodies. Approximately 10% of clients develop inhibitors to Factor VIII, which leads to a significantly decreased response. Antihemophilic factor contains traces of blood group A and B isohemagglutins. These may cause
intravascular hemolysis in clients with types A, B, or AB blood.
Both hepatitis and AIDS may be transmitted from AHF prepared from human plasma.
Powder for injection
Individualized, depending on severity of bleeding, degree of deficiency, body weight, and presence of inhibitors of factor VIII.
NOTE: AHF levels may rise 2% for every unit of AHF per kilogram administered. The following formula provides a guide for dosage calculation:
Expected Factor VIII increase (in % of normal):
AHF/IU administered x 2 ÷ body weight (in kg)
Dosages given are only guidelines.
Prophylaxis of spontaneous hemorrhage.
Increase AHF levels to about 5% of normal; 30% of normal is the minimum required for hemostasis following surgery and trauma. A single dose of 10 IU/kg (increases of approximately 20%) may be sufficient for mild superficial bleeds or early hemorrhages. Smaller doses may be sufficient for early hemarthrosis.
Single infusion to achieve AHF levels of at least 30%. Dosage should not be repeated.
Minor surgery, moderate hemorrhage.
AHF levels should be raised to 30%-50% of normal.
Initial: 15-25 IU/kg;
if necessary: 10-15 IU/kg q 8-12 hr.
Increase AHF levels to 80%-100% of normal.
Initial: 40-50 IU/kg;
maintenance: 20-25 IU/kg q 8-12 hr.
Raise AHF levels to 80%-100% of normal. Administer 1 hr before surgery; one-half the priming dose may be given 5 hr after the first dose. AHF levels should be maintained at 30% of normal for at least 10-14 days.
Factor VIII level should be increased to 50% immediately before the procedure.