Dosage regimen and duration of treatment depend on the severity of hemostatic function, localization and duration of bleeding, as well as the clinical condition of the patient.Treatment should be conducted under the supervision of a specialist and with regular laboratory monitoring of the concentration of anti-hemophilic factor (AGF) in the patient's blood plasma.
According to the WHO standard, the amount of factor VIII is expressed in international units (ME). The activity of factor VIII in plasma is expressed either as a percentage (relative to normal human plasma) or in international units (in relation to the International Standard of Factor VIII in plasma). One international unit (1 ME) is approximately equal to the level of activity of factor VIII in 1 ml of normal human plasma.
On each vial with the preparation, the content of factor VIII in it is shown, expressed in ME.
The formula for calculating the dose:
Required dose (ME) = (Body weight, kg x required% increase in factor VIII) / 2% / IU / kg.
Example of calculating the dose for a child weighing 40 kg:
(40 kg x 70%) / 2% / IU / kg = 1400 ME
Careful monitoring of ongoing therapy is especially necessary in the case of major surgery or when life-threatening bleeding occurs. Although the dose can be calculated according to the formulas given above, it is recommended to monitor regularly the content of factor VIII in the blood plasma of patients for monitoring.
If the required level of factor VIII in the blood plasma can not be reached or the bleeding is not controlled when administering the calculated doses of the drug, an inhibitor should be suspected. The presence of an inhibitor can be detected by appropriate laboratory tests and expressed in terms of the number of International Units (ME) of factor VIII, neutralized in each ml of plasma of blood (Bethesda units) or a common defined volume of blood plasma. If the inhibitor titer is less than 10 units of Bethesda per ml, the administration of an additional dose of factor VIII can neutralize its effect, and thus the administration of an additional dose of the drug should elicit the expected response. In this situation, careful laboratory monitoring of the level of factor VIII in blood plasma is necessary. If the inhibitor titer is more than 10 Bethesda units per ml, control of hemostasis with standard dose therapy of factor VIII is not achieved. In this situation, the drug is used in doses corresponding to the regime of induction of immune tolerance.
Recommendations for the dosage regimen for children, including newborns and adults, are given in Table 1. The dose and multiplicity of drug administration should always be correlated with clinical efficacy in each case.
Table 1. Schemes of introduction
| Hemarthroses, hemorrhages in the muscles of moderate severity or bruises | 30-60 | Repeated intravenous infusion every 12-24 hours. At least 3 days before complete relief of pain syndrome and recovery of motor activity |
| Life-threatening bleeding, such as bleeding from the throat, bleeding into the abdominal cavity, intracranial hemorrhage | 60- 100 | Repeated intravenous administration every 8-24 hours until the bleeding ceases completely |
| Type of operation (surgical intervention) |
| Small surgical interventions, including extraction of teeth | 30-60 | Single intravenous administration of the drug in combination with oral antifibrinolytic therapy for 1 hour is usually effective in 70% of cases. Then every 24 hours, at least 1 day, until complete recovery |
| Large surgical interventions | 80-100 | Repeated intravenous injections every 8-24 hours, depending on the clinical condition of the patient |
The table shows the values of the peak activity of factor VIII in patients with the expected mean half-life of factor VIII. If necessary, the peak activity should be measured within half an hour after the administration of the drug.For patients with a relatively short half-life of factor VIII, an increase in the dose and / or frequency of administration of the drug may be required.
The recombinant can also be used to prevent bleeding (short or prolonged course of therapy), if the attending physician considers it necessary. For long-term prophylaxis of bleeding in patients with severe haemophilia A, a dose of 20-40 IU / kg administered after 2-3 days is recommended.
Use in children
The recombinant can be used in children of all age groups, including newborns. The dosing regimen for "on demand" therapy is the same as for adults. With prolonged preventive treatment in severe hemophilia, in some cases higher doses or more frequent administration may be required, compared with those in adults.
Preparation and administration of the solution
The drug is administered intravenously after reconstitution with the applied solvent (sterile water for injections). The speed of the drug should be selected in such a way as to provide the patient with maximum comfort. The rate of administration should not exceed 10 ml / min.
A sterile disposable plastic syringe supplied with the drug should be used. Do not use the drug if the sterility of the package has been compromised. When dilution is necessary to comply with appropriate aseptic technique.
Preparation of the drug solution
Observe the rules of asepsis!
1. Heat the vials with the preparation and the solvent (sterile water for injection) to room temperature (15-25 ° C).
2. Remove the protective caps from the vials with the preparation and the solvent and expose the rubber stoppers.
3. Treat the cork with alcohol wipes. Place the vials on a flat surface.
4. Remove the protective cap from one end of the double-sided needle and pierce the stopper of the solvent vial with this end of the needle.
5. Remove the protective cap from the other end of the double-sided needle. Turn the vial with the solvent over and quickly pierce the center of the vial with the drug with the free end of the needle. Due to the vacuum, the solvent will flow into the vial with the drug.
6. Disconnect the vials by removing the needle from the vial of the vial with the solvent, and then remove the needle from the vial with the drug. Gently shake the bottle until the drug dissolves completely.Make sure that the entire preparation is completely dissolved, otherwise it will remain on the needle filter when taking the solution into the syringe.
Administration of the drug
Observe the rules of asepsis!
Enter intravenously at room temperature no later than 3 hours after the preparation of the solution.
The prepared solution can not be cooled.
Intravenous injection with a syringe
Before introduction, inspect for any discoloration or presence of mechanical inclusions in the solution. The solution should be clear or slightly opalescent, colorless or pale yellow in color.
It is recommended to use plastic syringes, since with the use of preparations of this type, the inner surface of glass syringes usually becomes sticky.
1. Attach the filter needle to the disposable syringe and pull the plunger toward yourself to draw air into the syringe.
2. Insert the needle into the vial with the prepared solution of the RECOMBINAT preparation.
3. Enter the air into the vial, and then draw the solution into the syringe.
4. Connect the injection system to the syringe. To introduce intravenously. The rate of drug administration should not exceed 10 ml per minute. It is necessary to monitor the patient's pulse before and during the administration of the drug.If a significant tachycardia occurs, the rate of administration should be reduced or the drug should be temporarily discontinued, which usually leads to rapid relief of symptoms.
5. The contents of each vial should be typed through a separate unused needle filter (please note that the needle filter is for the contents of only one vial!).