1 Dosing Considerations • Health Professionals should strongly consider administration of hepatitis A and hepatitis B vaccines to individuals receiving plasma derivatives. Potential risks and benefits of vaccination should be carefully weighed by the health professional and discussed with the patient.
• In pediatric patients, dosing should be based upon body weight (kg) in accordance to recommendations for dosing and administration for adults. 2 Recommended Dose and Dosage Adjustment Therapy for Hemophilia A Each vial of Humate-P® contains the labeled amount of Factor VIII activity in international unit (IU FVIII) for the treatment of hemophilia A.
It is important to calculate the dose using the number of IU of coagulation activity (FVIII:C) specified. As a general rule, 1 IU of Factor VIII activity per kg body weight will increase the circulating Factor VIII level by approximately 2 IU FVIII/dL.
Adequacy of treatment must be judged by the clinical effects; thus, the dosage may vary with individual cases. Although dosage must be individualized according to the needs of the patient (weight, severity of hemorrhage, presence of inhibitors), the following general dosages are recommended for adult patients: HUMATE-P®, Antihemophilic Factor/von Willebrand Factor Complex (Human) Page 6 of 36 Unclassified / Non classifié Table 1 – Dosage recommendations for the treatment of Hemophilia A Hemorrhagic event Dosage (IU FVIII/kg body weight) Minor hemorrhage: • Early joint or muscle bleed • Severe epistaxis Loading dose 15 IU FVIII/kg to achieve FVIII:C plasma level of approximately 30% of normal; one infusion may be sufficient.
If needed, half of the loading dose may be given once or twice daily for 1-2 days. Moderate hemorrhage: • Advanced joint or muscle bleed • Neck, tongue or pharyngeal hematoma (without airway compromise) • Tooth extraction • Severe abdominal pain Loading dose 25 IU FVIII/kg to achieve FVIII:C plasma level of approximately 50% of normal, followed by 15 IU FVIII/kg every 8-12 hours for first 1-2 days to maintain FVIII:C plasma level at 30% of normal, and then the same dose once or twice a day for a total of up to 7 days, or until adequate wound healing.
Life-threatening hemorrhage: • Major operations • Gastrointestinal bleeding • Neck, tongue or pharyngeal hematoma with potential for airway compromise • Intracranial, intraabdominal or intrathoracic bleeding • Fractures Initially 40 to 50 IU FVIII/kg, followed by 20-25 IU FVIII/kg every 8 hours to maintain FVIII:C plasma level at 80-100% of normal for 7 days, then continue the same dose once or twice a day for another 7 days in order to maintain the FVIII:C level at 30-50% of normal.
Ref:
Levine and Brettler DB (1991) Clinical aspects and therapy for hemophilia A. In: Hematology – Basic Principles and Practice. In all cases, the dose should be adjusted individually by clinical judgment of the potential for compromise of a vital structure, and by frequent monitoring of factor VIII activity in the patient’s plasma.
Therapy for Von Willebrand Disease Each vial of Humate-P® contains the labeled amount of von Willebrand Factor: Ristocetin Cofactor (VWF:RCo) activity expressed in international unit (IU VWF) for the treatment of VWD. It is important to calculate the dose using the number of IU VWF specified.
The dosage should be adjusted according to the extent and location of bleeding. As a rule, 40- 80 IU VWF per kg body weight are given every 8 to 12 hours. Repeat doses are administered for as long as needed based on repeat monitoring of appropriate clinical and laboratory measures.
0 IU VWF/dL rise per IU VWF/kg administered. The administration of 1 IU of Factor VIII per kg body weight can be expected to lead to a rise in circulating VWF of approximately 5 IU VWF/dL. The following Table provides dosing guidelines for pediatric and adult patients.
g. severe or refractory epistaxis, GI bleeding, CNS trauma, or traumatic hemorrhage) 40 to 50 IU VWF/kg every 8 to 12 hours for 3 days to keep the nadir level of VWF:RCo >50%; then 40 to 50 IU VWF/kg daily for a total of up to 7 days of treatment.
g. epistaxis, oral bleeding, menorrhagia) 40 to 50 IU VWF/kg (1 or 2 doses). g. severe or refractory epistaxis, GI bleeding, CNS trauma, hemarthrosis or traumatic hemorrhage) 40 to 60 IU VWF/kg every 8 to 12 hours for 3 days to keep the nadir level of VWF:RCo >50%; then 40 to 60 IU VWF/kg daily for a total of up to 7 days of treatment.
Factor VIII:C levels should be monitored and maintained according to the guidelines for hemophilia A therapy, Table 1 Types 2 (all variants) and 3 Minor (clinical indications above) 40 to 50 IU VWF/kg (1 or 2 doses) Major (clinical indications above) 40 to 80 IU VWF/kg every 8 to 12 hours for 3 days to keep the nadir level of VWF:RCo >50%, then 40 to 60 IU VWF/kg daily for a total of up to 7 days of treatment.
Factor VIII:C levels should be monitored and maintained according to the guidelines for hemophilia A therapy, Table 1.
Ref:
Scott and Montgomery (1993) Therapy of von Willebrand disease. Seminars in Thrombosis and Hemostasis, 19:37. Prevention of Excessive Bleeding During and After Surgery in VWD The following information provides guidelines for calculating loading and maintenance doses of Humate-P® for patients undergoing surgery.
However, in the case of emergency surgery, administer a loading dose of 50 to 60 IU VWF/kg and, subsequently, closely monitor the patient’s trough coagulation factor […]