powder and solvent for solution for injection
human von Willebrand factor
You should carefully read the contents of this leaflet before using the medicine because it contains important information for the patient.
Willfact is made from human plasma (the liquid part of the blood) and contains the active substance human von Willebrand factor (vWF).
vWF is involved in blood clotting. Lack of this factor, as in von Willebrand disease, means that blood does not clot as quickly as it should, resulting in an increased tendency to bleed. Replacing vWF with Willfact temporarily corrects the blood clotting mechanism.
Willfact is indicated for the prevention of bleeding associated with surgical procedures and other bleeding, as well as treatment in patients with von Willebrand disease, if treatment with only desmopressin (DDAVP) is ineffective or contraindicated.
Willfact can be used in all age groups.
Willfact should not be used to treat hemophilia A.
Treatment with Willfact should always be monitored by a doctorexperienced in the treatment of bleeding disorders.
If you have severe bleeding and blood tests confirm a decrease in factor VIII, you will receive a factor VIII concentrate and a vWF preparation within the first 12 hours.
Allergic reactions
Allergic hypersensitivity reactionsmay occur, similar to those after administration of other protein-based intravenous drugs derived from human blood or plasma.
You will be monitored during injection to detect early signs of hypersensitivity.
These include rash (hives or generalized urticaria), feeling of pressure in the chest, wheezing, decreased blood pressure (hypotension), and severe allergic reactions (anaphylaxis).
Your doctor will inform you about warning signs of an allergic reaction.
If you experience any objective or subjective signs of hypersensitivity, treatment should be discontinued and medical help sought immediately.
Viral safety
When manufacturing drugs from human blood or plasma, certain measures are taken to prevent the transmission of infections to patients. These include:
Despite these measures, when administering drugs produced from human blood or plasma, it is not possible to completely rule out the possibility of transmitting an infection. This also applies to unknown or newly emerging viruses or other types of infections.
The measures taken are considered effective against enveloped viruses, such as human immunodeficiency virus (HIV, which causes AIDS), hepatitis B virus, and hepatitis C virus.
The measures taken have limited value against non-enveloped viruses, such as hepatitis A virus and parvovirus B19. Parvovirus B19 infection can be serious in pregnant women (as there is a risk of infecting the unborn child) and patients with weakened immune systems or certain types of anemia (e.g., sickle cell anemia or hemolytic anemia).
Vaccinations
Your doctor may recommend that you receive vaccinations against hepatitis A and B if you regularly/repeatedly receive human von Willebrand factor derived from plasma.
Recording the batch number
It is strongly recommended that when administering each dose of Willfact, the patient's name and batch number of the medicine be recorded to document which batches of the medicine were administered.
Tell your doctor or pharmacist about all the medicines you are taking, have recently taken, or might take.
Willfact can be used in pregnant or breastfeeding women only if clearly necessary.
No controlled clinical trials have been conducted to assess the safety of Willfact in pregnant or breastfeeding women, and animal studies are insufficient to confirm safety in terms of fertility, pregnancy, and child development during pregnancy and after birth.
If you are pregnant or breastfeeding, think you may be pregnant, or plan to have a child, ask your doctor or pharmacist for advice before using this medicine.
No effects on the ability to drive or use machines have been observed.
One vial of 5 ml (500 IU) of Willfact contains 0.15 mmol (3.4 mg) of sodium.
This corresponds to 0.17% of the recommended maximum daily intake of sodium for an adult.
One vial of 10 ml (1000 IU) of Willfact contains 0.3 mmol (6.9 mg) of sodium.
This corresponds to 0.35% of the recommended maximum daily intake of sodium for an adult.
One vial of 20 ml (2000 IU) of Willfact contains 0.6 mmol (13.8 mg) of sodium.
This corresponds to 0.69% of the recommended maximum daily intake of sodium for an adult.
Treatment should be initiated and monitored by a doctor experienced in the treatment of bleeding disorders.
If your doctor decides that you can administer the medicine at home, they will instruct you accordingly.
This medicine should always be used exactly as your doctor has told you.
In case of doubt, consult your doctor.
It is recommended that Willfact be administered by a doctor or nurse. However, if you have been given Willfact to use at home, your doctor will ensure that you are informed about how to perform the injection and the correct dose. You should follow the doctor's instructions and ask for help if you have problems using the syringe. The syringe can only be used by a trained person.
Your doctor will calculate the correct dose of Willfact (expressed in international units - IU).
The dose depends on:
The dose is between 40-80 IU/kg body weight.
Your doctor will recommend blood tests to check:
Based on the results of these tests, your doctor may adjust the frequency of injections and the dose administered.
In some cases, it may be necessary to use a factor VIII preparation (another coagulation protein) in addition to Willfact to allow for faster treatment or prevention of bleeding (in emergency situations or in the case of acute bleeding).
Willfact can also be used for long-term prophylaxis, in which case the dose is also determined individually. Administering Willfact at a dose of 40-60 IU/kg body weight 2-3 times a week reduces the number of bleeding episodes.
If you think that Willfact is too strong or too weak, talk to your doctor.
Dosing in children and adolescents is based on body weight. In some cases, especially in younger patients (under 6 years), higher doses (up to 100 IU/kg body weight) may be necessary.
Detailed instructions for reconstitution and administration of the medicinal product are provided at the end of the leaflet.
No symptoms of overdose with Willfact have been reported, but in the event of administration of a large amount, the risk of thrombosis cannot be ruled out.
If you miss a dose of Willfact, consult your doctor.
Do not take a double dose to make up for a missed dose.
If you have any further questions on the use of this medicine, ask your doctor, pharmacist, or nurse.
Like all medicines, this medicine can cause side effects, although not everybody gets them.
Warning signs of an allergic reaction include:
If you experience any of these symptoms, stop treatment immediately and inform your doctorto initiate appropriate treatment, depending on the type and severity of the reaction.
In patients with von Willebrand disease, especially type 3, it is possible for proteins that neutralize the action of vWF to develop. Such proteins are called neutralizing antibodies or inhibitors. Patients treated with vWF should be closely monitored by their doctor for the development of inhibitors through appropriate clinical observation and laboratory tests. If inhibitors are present, this condition may manifest as an inadequate clinical response. It may also co-occur with severe allergic reactions.
There is a risk of blood clots (thrombosis), especially in patients at risk. After correcting the von Willebrand factor deficiency, patients should be monitored for early signs of thrombosis or disseminated intravascular coagulation and receive anti-thrombotic treatment in situations where the risk of thrombosis is increased (after surgery, in bedridden patients, in patients with a deficiency of a coagulation inhibitor or fibrinolytic enzyme).
If you are taking vWF preparations containing FVIII, the risk of thrombosis may be higher due to persistently elevated FVIII levels in the blood.
The following side effects are common(may affect up to 1 in 10 patients):
The following side effects are uncommon(may affect up to 1 in 100 patients):
If you experience any side effects, including those not listed in this leaflet, please inform your doctor, pharmacist, or nurse. Side effects can be reported directly to the Department of Drug Safety Monitoring of the Office for Registration of Medicinal Products, Medical Devices, and Biocidal Products:
Jerozolimskie Avenue 181C
02-222 Warsaw
Phone: +48 22 49 21 301
Fax: +48 22 49 21 309
Website: https://smz.ezdrowie.gov.pl
Side effects can also be reported to the marketing authorization holder.
Reporting side effects will help to gather more information on the safety of this medicine.
Keep this medicine out of the sight and reach of children.
Do not use this medicine after the expiry date stated on the vial label and carton.
Do not store above 25°C. Store in the original package to protect from light.
Do not freeze.
To maintain sterility, the product should be used immediately after reconstitution. However, chemical and physical stability has been demonstrated for 24 hours at 25°C.
Do not use this medicine if you notice turbidity or solid particles in the solution.
Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required. This will help protect the environment.
Active substanceis human von Willebrand factor (500 IU, 1000 IU, 2000 IU) expressed in international units of ristocetin cofactor activity (vWF:RCo).
After reconstitution with 5 ml (500 IU), 10 ml (1000 IU), or 20 ml (2000 IU) of water for injection, one vial contains approximately 100 IU/ml of human von Willebrand factor.
Before adding albumin, the specific activity of the solution is at least 60 IU vWF:RCo per 1 mg of total protein.
Other ingredients:
Powder: human albumin, arginine hydrochloride, glycine, sodium citrate, and calcium chloride dihydrate.
Solvent: water for injection.
Willfact is provided as a white or pale yellow powder or brittle solid and a clear, colorless solvent for solution for injection after reconstitution using a transfer system.
Willfact is available in pack sizes of 500 IU/5 ml, 1000 IU/10 ml, 2000 IU/20 ml.
The reconstituted solution should be clear or slightly opalescent, colorless or slightly yellow.
LFB-BIOMEDICAMENTS
3, avenue des Tropiques,
ZA de Courtaboeuf,
91940 LES Ulis,
FRANCE
pharmacovigilance@lfb.fr
LFB-BIOMEDICAMENTS
3, avenue des Tropiques,
ZA de Courtaboeuf,
91940 LES Ulis,
FRANCE
LFB-BIOMEDICAMENTS
59 Rue de Trévise
59000 LILLE
FRANCE
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Generally, administration of 1 IU/kg body weight of von Willebrand factor increases the activity of circulating vWF:RCo by approximately 0.02 IU/ml (2%).
Aim to achieve vWF:RCo levels of >0.6 IU/ml (60%) and FVIII:C levels of >0.4 IU/ml (40%).
Hemostasis is uncertain until the coagulant activity of factor VIII (FVIII:C) reaches 0.4 IU/ml (40%). Administration of von Willebrand factor alone does not result in maximum increase in FVIII:C activity for at least 6-12 hours. It is not sufficient for immediate normalization of FVIII:C activity. Therefore, if the initial FVIII:C activity is below the critical value and rapid correction of hemostasis is necessary - as in the case of bleeding, severe trauma, or emergency surgery - factor VIII should be administered with the first dose of von Willebrand factor to achieve hemostatic levels of FVIII:C in the blood.
In the case of planned surgery, the first injection of Willfact should be given 12-24 hours before the procedure, and the second injection - immediately before the procedure. In such cases, concurrent administration of factor VIII preparation is not necessary, as the endogenous FVIII:C level usually reaches the critical value of 0.4 IU/ml (40%) before the procedure. However, this should be confirmed in each patient.
Children and adolescents
The dose for each indication is based on body weight. The dose and duration of treatment should be adjusted according to the patient's clinical condition and vWF:RCo and FVIII:C levels in the blood.
Scheduled surgery
Intravenous administration
Reconstitution
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The powder should dissolve in less than 5 minutes, usually instantly.
The resulting solution should be clear or slightly opalescent, colorless or slightly yellow. Before administration, the reconstituted product should be visually inspected for particulate matter and discoloration.
Do not use a cloudy or precipitated solution.
Do not mix with other medicines.
Do not dilute the reconstituted product.
Administration
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Storage after reconstitution
To maintain sterility, the product should be used immediately after reconstitution. However, chemical and physical stability has been demonstrated for 24 hours at 25°C.
Any unused product or waste material should be disposed of in accordance with local requirements.
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