Source: Medicines & Healthcare Products Regulatory Agency (GB) Revision Year: 2015 Publisher: LFB-BIOMEDICAMENTS, 3, avenue des Tropiques, BP 40305 LES ULIS, 91958 Courtabœuf Cedex, FRANCE
Willfact is indicated in the prevention and treatment of haemorrhages or surgical bleeding in von Willebrand disease when desmopressin (DDAVP) treatment alone is ineffective or contraindicated.
Willfact should not be used in the treatment of haemophilia A.
Treatment of von Willebrand disease should be supervised by a physician experienced in the treatment of haemostatic disorders.
Generally, 1 IU/kg of von Willebrand factor raises the circulating level of VWF:RCo by 0.02 IU/ml (2%).
Levels of VWF:RCo of >0.6 IU/ml (60%) and of FVIII:C of >0.4 IU/ml (40%) should be achieved.
Haemostasis cannot be ensured until FVIII coagulant activity (FVIII:C) has reached 0.4 IU/ml (40%). A single injection of von Willebrand factor will only lead to a maximum increase in FVIII:C after at least 6-12 hours. The single administration of von Willebrand factor cannot immediately correct the FVIII:C level. If the patient’s baseline plasma FVIII:C level is below this critical level, in all situations where a rapid correction of haemostasis should be achieved, such as the treatment of haemorrhage, severe trauma or emergency surgery, it is necessary to administer a factor VIII product with the first injection of von Willebrand factor, in order to achieve a haemostatic plasma level of FVIII:C.
However, if an immediate rise in FVIII:C is not necessary, for example in a planned operation, or if the baseline FVIII:C level is sufficient to ensure haemostasis, the physician may decide to omit the co-administration of FVIII at the first injection.
The first dose of Willfact is 40 to 80 IU/kg for the treatment of haemorrhage or trauma, in conjunction with the required amount of factor VIII product, calculated according to the patient’s baseline plasma level of FVIII:C, in order to achieve an appropriate plasma level of FVIII:C, immediately before the intervention or as soon as possible after the onset of the bleeding episode or severe trauma. In case of surgery, it should be given 1 hour before the procedure.
An initial dose of 80 IU/kg of Willfact may be required, especially in patients with Type 3 von Willebrand disease where maintenance of adequate levels may require higher doses than in other types of VWD.
For elective surgery, treatment with Willfact should start 12-24 hours before surgery and should be repeated 1 hour before the procedure. In this case, co-administration of factor VIII product is not required since endogenous FVIII:C has usually reached the critical level of 0.4 IU/ml (40 %) before surgery. However, this should be confirmed in each patient.
If required, treatment should be continued with an appropriate dose of Willfact, with 40-80 IU/kg per day in 1 or 2 injections daily over one to several days. The dose and duration of the treatment depend on the clinical status of the patient, the type and severity of bleeding and both VWF:RCo and FVIII:C levels.
Willfact can be administered as long-term prophylaxis in a dose which is determined individually for each patient. Willfact doses between 40 and 60 IU/kg, administered two to three times per week, reduce the number of haemorrhagic episodes.
There is no data from a clinical study to characterise the response to use of Willfact in children less than 6 years of age.
The use of Willfact in children under 12 years of age is only documented in individual cases; the use of Willfact in patients previously untreated with von Willebrand factor is not documented in the clinical studies.
The product should be administered via the intravenous route at a maximum rate of 4 ml/minute.
For instructions on reconstitution of the medicinal product before administration, see section 6.6.
No case of overdose with Willfact has been reported.
Thromboembolic events may occur in case of major overdose.
3 years.
Chemical and physical in-use stability has been demonstrated for 24 hours at 25°C.
From a microbiological point of view, the product should be used immediately. If not used immediately, in-use storage times and conditions prior to use are the responsibility of the user.
Do not store above 25°C. Store in the original package in order to protect from light. Do not freeze.
For storage conditions after reconstitution of the medicinal product, see section 6.3.
1 pack contains: powder in a vial (Type I glass) with a bromobutyl stopper, solvent in an injection vial (Type I glass) with a chlorobutyl stopper, and a transfer system.
Reconstitution:
The currently applicable guidelines for aseptic procedures must be followed. The transfer system is only used to reconstitute the drug, as described below. It is not intended in administering the drug to the patient.
The powder generally dissolves instantaneously and should have dissolved in less than 10 minutes.
The solution should be clear or slightly opalescent, colourless or slightly yellowish.
Administration:
Any unused product or waste material should be disposed of in accordance with local requirements.
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