s known or suspected to be inadequate)
Major†
(e.g., severe or refractory epistaxis, GI bleeding, CNS trauma, traumatic hemorrhage) Loading dose 40-60 IU/kg.
Then 40-50 IU/kg every 8-12 hours for 3 days to keep the trough level of VWF:RCo >50%.
Then 40-50 IU/kg daily for up to 7 days.
Type 1 VWD – Moderate or severe (baseline VWF:RCo typically <30%) Minor
(e.g., epistaxis, oral bleeding, menorrhagia) 40-50 IU/kg (1 or 2 doses).
Major
(e.g., severe or refractory epistaxis, GI bleeding, CNS trauma, hemarthrosis, traumatic hemorrhage) Loading dose 50-75 IU/kg.
Then 40-60 IU/kg every 8-12 hours for 3 days to keep the trough level of VWF:RCo >50%.
Then 40-60 IU/kg daily for up to 7 days.
Type 2 VWD (all variants) and Type 3 VWD Minor
(clinical indications above) 40-50 IU/kg (1 or 2 doses).
Major
(clinical indications above) Loading dose 60-80 IU/kg.
Then 40-60 IU/kg every 8-12 hours for 3 days to keep the trough level of VWF:RCo >50%.
Then 40-60 IU/kg daily for up to 7 days.
2.3Prevention 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 International Units (IU) VWF:RCo/kg body weight and, subsequently, closely monitor the patient's trough coagulation factor levels.
Measure incremental IVR and assess plasma VWF:RCo and FVIII:C levels in all patients prior to surgery when possible.
To determine IVR:
Measure the baseline plasma VWF:RCo level.
Infuse a calculated dose [International Units (IU)/kg] of VWF:RCo product intravenously at "time 0".
At "time+30 minutes", measure the plasma VWF:RCo level.
Use the following formula to calculate IVR:
IVR= (Plasma VWF:RCotime+30 min – Plasma VWF:RCobaseline International Units (IU)/dL)
Calculated dose (International Units (IU)/kg)
For example, assuming a baseline VWF:RCo of 30 International Units (IU)/dL at "time 0", a calculated dose of 60 International Units (IU)/kg, and a VWF:RCo of 120 International Units (IU)/dL at "time+30 minutes", the IVR would be 1.5 International Units (IU)/dL per International Units (IU)/kg of VWF:RCo administered.
Loading Dose
Table 3 provides guidelines for calculating the loading dose for adult and pediatric patients based on the target peak plasma VWF:RCo level, the baseline VWF:RCo level, body weight in kilograms, and IVR. When individual recovery values are not available, a standardized loading dose can be used based on an assumed VWF:RCo IVR of 2.0 International Units (IU)/dL per International Unit (IU)/kg of VWF:RCo administered.
Table 3: VWF:RCo and FVIII:C Loading Dose Calculations for the Prevention of Excessive Bleeding During and After Surgery for All Types of VWD Type of Surgery VWF:RCo Target Peak Plasma Level FVIII:C Target Peak Plasma Level Calculation of Loading Dose
(to be administered 1 to 2 hours before surgery)
IU = International Units.
BW = body weight.
*
Δ = Target peak plasma VWF:RCo level – baseline plasma VWF:RCo level.
†
IVR = in vivo recovery as measured in the patient.
‡
Oral surgery is defined as extraction of fewer than three teeth, if the teeth are non-molars and have no bony involvement. Extraction of more than on |
