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

Adverse 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.

Mechanism 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.