Medically reviewed by Fedorchenko Olga Valeryevna, PharmD. Last updated on 2022-03-26
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Antihemophilic Factor Ix
Lyophilizate for the preparation of a solution for intravenous administration
Treatment and prevention of bleeding in patients with hemophilia B (congenital or acquired coagulation factor IX deficiency).
V/v (after dissolving in water for injection, which is included in the package of the drug). Treatment should be initiated under the supervision of a specialist in antihemophilic therapy. The dose and duration of therapy depend on the degree of blood clotting factor IX deficiency, the location and intensity of bleeding, and the patient's clinical condition.
Calculation of the administered dose: The number of units of blood clotting factor IX administered is expressed in international units (ME) in accordance with the WHO standards for blood clotting factor IX preparations. The activity of the factor itself in the plasma is expressed in the same ME or in % relative to its content in normal plasma. The calculation of the required dose is based on the statement that the introduction of 1 ME of blood clotting factor IX per 1 kg of body weight of the patient increases the activity of this factor in the body by 1.3%.
The calculation is carried out according to the formula:
Required dose (ME) = body weight (kg) × desired level of blood clotting factor IX IU / dl × 0.8.
It should be borne in mind that the amount and frequency of use always depends on the individual clinical effect. Blood clotting factor IX drugs are usually not used more than 1 time/day.
Approximate doses of the drug are shown in the table.
The severity of haemorrhage/type of surgery
Required level of blood clotting factor IX, %
Frequency of administration and duration of therapy
|Early hemarthrosis, bleeding with traumatic damage to the vessels of the limb||20–40||1 time/day until the bleeding stops (pain relief)|
|Intensive: hemarthrosis, bleeding with traumatic damage to the vessels of the limb, hematoma||30–60||1 time/day 3-4 days or longer until the pain or immobility disappears|
|Life-threatening: intraperitoneal, neck, craniocerebral||60–100||Every 8-24 hours until the end of the threat to life|
|Minor surgeries, including the removal of teeth||30–60||Every 24 hours until recovery|
|Serious (abdominal) operations (before and after surgery)||80–100||Every 8-24 hours until the wound heals, then for 7 days to maintain the factor level within 30-60%|
In some cases, especially when the initial dose is administered, higher doses of the drug are required.
The clinical response to the introduction of blood clotting factor IX is individual, so it is also recommended to determine the level of this factor in the blood against the background of the treatment, especially in cases of serious surgical interventions.
For the purpose of long-term prevention of bleeding in severe hemophilia, the drug is administered at a dose of 20-30 IU / kg 2 times / week. Sometimes (especially at a young age) the drug should be administered more often or in large doses.
It is necessary to monitor the possible formation of antibodies to blood clotting factor IX in the patient. The determination of antibodies should be carried out in the absence of the effect of an adequate dose or if it is impossible to achieve the desired level of the factor in the plasma with its adequate administration. If the level of the inhibitor does not exceed 10 units of Bethesda (BE) per 1 ml when determining (the Bethesda test), the introduction of additional doses of factor IX usually leads to its neutralization and the desired clinical effect. If the antibody level exceeds 10 BE, the use of activated PPSB (prothrombin complex factor concentrate) or activated factor VII should also be considered. Such treatment should be carried out only by specialists in the field of antihemophilic therapy
Rules for the preparation and administration of the solution
Bring the solvent (water for injection) and concentrate in closed vials to room temperature. If a water bath is used to warm the solvent, make sure that the water does not come into contact with the rubber stoppers or bottle caps. The temperature of the water bath should not exceed 37 °C.
Remove the protective caps from the concentrate bottle and the water bottle and disinfect the rubber stoppers of both bottles with one of the disinfectant wipes. Release the short end of the double-ended needle from the plastic packaging, pierce the water bottle with it and press down until it stops. Turn the water bottle over with the needle, release the long end of the two-point needle, pierce the concentrate bottle with it and push down until it stops. The vacuum in the concentrate bottle will draw in the water. Separate the bottle of water together with the needle from the bottle of concentrate. The drug will quickly dissolve, for this the bottle needs only a slight shake. Only a colorless, transparent solution without sediment is allowed for use
The ready-to-use drug should be administered immediately after dissolution. As a preventive measure, it is necessary to monitor the pulse rate before and during the administration of the drug. With a pronounced increase in the pulse rate, it is necessary to take a break or reduce the speed of administration.
With a filter needle, pierce the rubber stopper of the concentrate bottle. Connect the other end of the needle to a disposable syringe. Turn the bottle over and fill the syringe with the solution. Disinfect the skin at the injection site. Release the syringe with the solution and attach the butterfly needle, make an intravenous injection. Inject the solution into the vein at a rate of 2-3 ml / min.
If the patient receives more than one bottle of the drug, the same disposable cannula (butterfly needle) may be used. The syringe can also be used for several vials of the drug. However, for a set of ready-to-use solution, a new filter needle must be used each time.
The solution remaining after the injection must be destroyed.
hypersensitivity to the components of the drug,
acute myocardial infarction,
acute renal failure,
With caution The drug should be prescribed to children under the age of 6 years, in whom blood clotting factor IX drugs were rarely used, and to patients who had not previously been treated.
Allergic reactions: rarely-allergic reactions, increased body temperature, in isolated cases-anaphylactic reactions (sometimes coinciding with the formation of an inhibitor to blood clotting factor IX. The necessary therapy depends on the type and severity of the reaction.
From the blood clotting system: thromboembolic complications are possible (a high-purity drug is rarely associated with such reactions, but in the past, when using low-purity drugs, myocardial infarction, venous thrombosis, pulmonary embolism and DIC syndrome have occurred). Given the presence of heparin in the drug, in exceptional cases, a sudden decrease in the number of platelets by 50% compared to the initial one (thrombocytopenia, type II) is possible immediately after administration of the drug or 6-14 days after treatment (in the presence of a history of hypersensitivity to heparin). Severe thrombocytopenia may be accompanied by thrombosis, consumption coagulopathy, petechiae, black stools. In these cases, the use of Agemfil B should be discontinued and the patient should not be prescribed heparin-containing drugs
There are no reports of symptoms of Agemfil B overdose.
The drug is involved in the processes of blood clotting, promotes the transition of prothrombin to thrombin and the formation of a fibrin clot in patients with hemophilia. Injections of Agemfil B increase the activity of blood clotting factor IX to 30-60%.
About 30-50% of blood clotting factor IX is detected in the blood immediately after infusion, T1/2 - up to 29.1 h. The specific activity of Agemfil B is approximately 100 IU / mg of protein.
- Coagulants (including blood clotting factors), hemostatics
Agemfil B is incompatible with other drugs, as additional activation or inactivation of blood clotting factor IX is possible.