Factor VIII
Indications
Factor VIII is used for:
Haemophilia A, Haemorrhage
Adult Dose
Intravenous
Hemophilia A
Minor hemorrhage: 15 IU/kg loading dose to achieve FVIII:C plasma level ~30% of normal; THEN may administer half of loading dose qDay or q12hr for 1-2 days if a second infusion necessary
Moderate hemorrhage/minor surgery: 25 IU/kg loading dose to achieve FVIII:C plasma level ~50% of normal; THEN administer FVIII:C 15 IU/kg IVq8-12hr for 1-2 days to maintain plasma levels of FVIII:C at 30% of normal; repeat dose qDay or q12hr for up to 7 days or until adequate would healing achieved
Severe hemorrhage/major surgery: 40-50 IU/kg loading dose THEN administer FVIII:C 20-25 IU/kg IVq8-12hr to maintain plasma levels of FVIII:C at 80-100% of normal for 7 days; continue dose qDay or q12hr for up to 7 days to maintain FVIII: C levels at 30% to 50% normal
Child Dose
Intravenous
Hemophilia A
Minor hemorrhage: 15 IU/kg loading dose to achieve FVIII:C plasma level ~30% of normal; THEN may administer half of loading dose qDay or q12hr for 1-2 days if a second infusion necessary
Moderate hemorrhage/minor surgery: 25 IU/kg loading dose to achieve FVIII:C plasma level ~50% of normal; THEN administer FVIII:C 15 IU/kg IVq8-12hr for 1-2 days to maintain plasma levels of FVIII:C at 30% of normal; repeat dose qDay or q12hr for up to 7 days or until adequate would healing achieved
Severe hemorrhage/major surgery: 40-50 IU/kg loading dose THEN administer FVIII:C 20-25 IU/kg IVq8-12hr to maintain plasma levels of FVIII:C at 80-100% of normal for 7 days; continue dose qDay or q12hr for up to 7 days to maintain FVIII: C levels at 30% to 50% normal
Renal Dose
Administration
Contra Indications
Hypersensitivity
Precautions
Risk of intravascular haemolysis in patients with blood groups A, B, or AB receiving high doses or repeated doses of factor VIII preparations. Risk of transmission of some viral infections especially hepatitis B and C. Dose requirement may vary in patients with factor VIII inhibitors; thus optimal treatment should be based on clinical response. Monitor platelet counts regularly during treatment. Pregnancy, lactation.
Lactation: Excretion in milk unknown; use with caution
Pregnancy-Lactation
Pregnancy Category: C
Lactation: Excretion in milk unknown; use with caution
Interactions
Side Effects
Side effects of Factor VIII :
Allergic reactions e.g. chills, chest tightness, fever, headache, hyperfibrinogenaemia, jittery feeling, lethargy, nausea, vomiting, somnolence, stinging at infusion site, stomach discomfort, tingling, urticaria, vasomotor reactions with rapid infusion.
Mode of Action
Factor VIII is required for clot formation and maintenance of haemostasis. It activates factor X in conjunction with activated factor IX. Activated factor X then converts prothrombin to thrombin, which converts fibrinogen to fibrin, and forms a stable clot with factor XIII. Factor VIII is used for replacement therapy in patients with haemophilia A.