Index of drugs

Treatment and prophylaxis of bleeding in patients with haemophilia A (congenital factor VIII deficiency). The drug does not contain a pharmacologically effective amount of von Willebrand factor, therefore it can not be used to treat von Willebrand disease.

1 vial contains nominally 250 IU, 500 IU. or 1000 IU human coagulation factor VIII. It contains sodium (less than 1 mmol (23 mg) / vial of 250 IU, up to 1.75 mmol (40 mg) / vial of 500 IU and up to 1.75 mmol (40 mg) / vial of 1,000 IU).

Anti-haemorrhagic drug, blood coagulation factor VIII. Coagulation factor VIII is in the form of a bimolecular complex with von Willebrand factor (FVIII and vWF), which performs various physiological functions. When administered to patients with haemophilia, factor VIII is combined with von Willebrand factor in the patient's circulation. Active factor VIII acts as a cofactor of active factor IX, accelerating the conversion of factor X to active factor X. The active factor X converts prothrombin into thrombin. The thrombin then converts fibrinogen into a fibrin that allows clot formation. After injection, about 2/3 to 3/4 of factor VIII remains in the circulation. The level of factor VIII activity achieved in plasma should be between 80% and 120% of the predicted factor VIII activity. Factor VIII activity in factor VIII decreases in a two-phase exponential distribution. In the initial phase, the distribution between endovascular and other compartments (body fluids) takes place with a plasma elimination half-life ranging from 3 to 6 h. In the Next, slower phase, which probably reflects the consumption of factor VIII T_0,5 is from 8 to 20 h.

Hypersensitivity to the active substance or any of the ingredients.

If hypersensitivity symptoms occur, the preparation should be discontinued immediately. Standard methods to prevent infections caused by the use of preparations obtained from human blood or plasma include the selection of donors, testing of individual donations and pools of plasma for specific markers of infection and the use of effective methods in the production process to inactivate / remove viruses. Nevertheless, when administered with preparations obtained from human blood or plasma, the possibility of transmitting an infectious agent can not be completely ruled out. This also applies to unknown or new viruses and other pathogens. The methods used are considered effective for enveloped viruses such as HIV, HBV and HCV and may have limited efficacy against non-enveloped viruses such as HAV and parvovirus B19 (may be dangerous for pregnant women and for immunodeficient patients or excessive erythropoiesis). Adequate vaccinations are recommended (against hepatitis A and B) in patients who receive regular or repeat preparations containing human coagulation factor VIII. The development of neutralizing antibodies (inhibitors) of factor VIII is a known complication in the treatment of haemophilia A patients - patients should be monitored for the development of inhibitor antibodies through appropriate clinical observation and laboratory testing. There have been reports in the literature showing a correlation between the occurrence of factor VIII inhibitors and allergic reactions. Patients with allergic reactions should be tested for the presence of an inhibitor because of the increased risk of anaphylaxis induced by factor VIII. Due to the risk of allergic reactions, the first administration of factor VIII should be carried out, under the decision of the attending physician, under medical supervision, in a place where appropriate medical assistance can be provided in case of allergic reactions. The drug contains sodium - 1 vial of 250 IU. contains less than 1 mmol (23 mg) sodium, i.e. the drug at this dose can be considered "free of sodium", while 1 vial 500 IU. or 1000 IU contains up to 1.75 mmol (40 mg) of sodium, which should be taken into account in patients on a sodium restricted diet.

Due to the rare occurrence of haemophilia A in women, there is no experience of using factor VIII during pregnancy and breastfeeding.Therefore, factor VIII during pregnancy and lactation should only be given when strictly indicated.

Rare: hypersensitivity reactions, fever, antibodies against factor VIII in the blood. Very rare: anaphylactic shock.

Intravenously, do not administer more than 2-3 ml / min. The dosage and duration of substitution therapy depends on the level of factor VIII deficiency, the place and extent of bleeding and the clinical condition of the patient. The number of units of factor VIII administered is expressed in International Units (IU) in accordance with the current standard for factor VIII preparations approved by WHO. Factor VIII activity in plasma is expressed either as a percentage (relative to normal human plasma) or in IU. in accordance with the international standard for factor VIII in plasma. 1 IU Factor VIII activity is equivalent to the amount of factor VIII in 1 ml of normal human plasma. The calculation of the required dose of factor VIII is based on empirical data that 1 IU factor VIII / kg body weight increases factor VIII activity in plasma by 1.5-2% of normal activity. The required dose is determined using the following formula: required number of units = mc. (kg) x required increase in factor VIII (%) (IU / dl) x 0.5. The dose and frequency of administration should be determined individually.Early bleeding into the joints, muscles or the mouth: the required level of factor VIII is 20-40% of the norm, the infusion should be repeated every 12-24 h, at least 1 day, until the pain caused by bleeding or healing of the wound disappears.More severe bleeding to the joints, muscles or hematoma: 30-60% of the norm, infuse every 12-24 h for 3-4 days or longer, until the pain and function return.Bleeds that threaten life60-100% of the standard, infuse every 8-24 h until the hazard disappears.Minor surgery, including tooth extraction: 30-60% of norm every 24 h, at least 1 day, until the wound heals.Serious surgery80-100% of the norm (before and after surgery), infusion repeated every 8-24 h until adequate wound healing, then continue therapy for at least 7 consecutive days to maintain factor VIII activity at 30-60% . Regular determination of factor VIII plasma levels is necessary to calculate the dose and to determine the frequency of infusion. In the long-term prophylaxis of bleeding in patients with severe haemophilia A, factor VIII should be administered at a dose of 20-40 IU. factor VIII / kg body weight at intervals of 2-3 days.