The solution obtained after the addition of the solvent to the lyophilizate is intended only for intravenous administration. Prepared solution is recommended to enter at a speed of no more than 2-3 ml per minute.
The dose of the drug and the duration of substitution therapy depend onthe severity of the coagulation factor VIII deficiency, the localization and severity of bleeding, and the clinical condition of the patient.
The activity of the drug is expressed in the International Units (ME), which comply with the current WHO standard for factor VIII preparations.
The activity of coagulation factor VIII in plasma is expressed either as a percentage (relative to normal human plasma) or in International Units (relative to the International Standard for factor VIII in plasma).
One International Unit (ME) of the coagulation factor VIII activity is equivalent to the amount of factor VIII in 1 ml of normal human plasma.
Calculation of the required dose is based on empirical design data (1 ME coagulation factor VIII per kg of body weight increases the activity of this factor in blood plasma for 1-2% normal activity) and is carried out according to the formula:
The required dose (ME) = body weight (kg) x desired level of factor increase (%) x 0.5
When choosing the dose and frequency of administration of the drug should always focus on clinical effectiveness in each individual case.
In the event of bleeding, the activity of coagulation factor VIII should not fall below a certain level of plasma activity (in% of normal content) in the relevant period.The presented table can be used to calculate the dose of the drug for various bleeding and surgical interventions:
| Severity of bleeding / Type of surgical intervention | Required level coagulation factor VIII | Frequency of administration and duration of therapy |
| Bleeding |
| Early hemarthroses, intramuscular bleeding, bleeding in oral cavity | 20-40% | Repeat every 12-24 hours. At least 1 day, before relief of pain or healing |
| More extensive hemarthroses, intramuscular bleeding or hematoma | 30-60% | Repeat administration every 12-24 hours for 3-4 days or more before cupping pain and recovery ability to work |
| Hemorrhages representing threat to life | 60-100% | Repeat the introduction every 8-24 hours to eliminate the threat to life |
| Surgical interventions |
| Small, including tooth extraction | 30-60% | Every 12-24 hours, no less than 1 day, until healing |
| Extensive | 80-100% (before and after- operating) | Repeat administration every 8-24 hours, until adequate wound healing, then not less than 7 days for maintaining activity coagulation factor VIII at the level of 30-60% |
During the course of treatment, it is necessary to control the level of coagulation factor VIII for correcting the applied dose and the frequency of repeated administration of the drug.Determination of the activity of the blood coagulation factor VIII in the plasma is mandatory for accurate control of substitution therapy, especially for extensive surgical interventions. Patients can individually respond to the administration of the drug, with a different level of recovery in vivo and a different half-life of the drug.
In the long-term prophylaxis of bleeding in patients with severe hemophilia A, the drug is usually given in a dose of 20-40 IU / kg body weight at intervals of 2-3 days. In some cases, especially in young patients, higher doses may be required or the intervals between administrations may be shortened.
In cases where the expected level of coagulation factor VIII activity was not achieved in the treatment, or if the bleeding did not stop after the administration of the appropriate dose of the drug, a patient should be examined for the presence of coagulation factor inhibitors VIII. If inhibitors are present in a titer of less than 10 Be / ml, the additional administration of coagulation factor VIII can stop bleeding. In patients with a titer of inhibitors above 10 BTU / ml or a high response rateshould consider the use of (activated) concentrate prothrombin complex or activated clotting factor VII.
Such patients should be directed under the supervision of doctors with experience in the treatment of hemophilia.
Instructions for preparation and introduction of the solution
You must strictly follow the rules of asepsis!
Dissolution of lyophilized powder
- Before opening, the bottles with the solvent and lyophilizate are heated to room temperature and maintained at this temperature (max 35 ° C) during the whole solution preparation time (about 10 min). If a water bath is used for heating, it is necessary to ensure that water Do not touch the cork or the lid of the vial.
- Remove the protective caps from the aluminum caps of both bottles to access the central part of the rubber stoppers (1).
- Rubber stoppers are wiped with a napkin impregnated with alcohol.
- Open the packaging of the device for adding a solvent with a built-in filter (2). The bottle with the solvent is placed vertically. Without removing the packaging, the blue part of the device for adding the solvent is placed on the bottle with the solvent (3).
- Remove the package, providing access to the transparent part of the device for adding the solvent.
- The solvent bottle and the solvent addition device mounted on it are turned upside down, the vial with the lyophilizate is placed vertically, the transparent part of the device for adding the solvent is put on the vial with the lyophilizate (4). Under the action of vacuum, the solvent enters the vial with lyophilizate (5). Immediately, as soon as the entire volume of the solvent has moved to the vial with the lyophilizate, the blue part of the device for adding the solvent is unscrewed together with the solvent vial (6). Gently rock the vial with the prepared solution until the lyophilizate is completely dissolved. Do not shake the bottle to avoid foaming. The prepared solution should be clear or slightly opalescent.
- The solution prepared for use should be used immediately after preparation. A muddy or viscous solution containing a solution is prohibited.&hide_Cookie=yes)
Introduction:
- After the lyophilizate is dissolved, the attached disposable syringe is screwed onto the transparent part of the device for adding the solvent (7) and the prepared solution is drawn into the syringe.A separate filter is not required, because the solvent addition device has a built-in filter.&hide_Cookie=yes)
- Carefully disconnect from the syringe the transparent part of the device for adding the solvent together with the vial and slowly inject the prepared solution intravenously using the attached venipuncture device (butterfly needle). The rate of administration should be 2-3 ml per minute.
- After using the butterfly needle to avoid injury, it is closed with a protective cap.