| Treatment should be initiated under the supervision of a physician experienced in the treatment of haemostatic disorders. Posology Factor VIII deficiency The dosage and duration of the substitution therapy depend on the severity of the factor VIII deficiency, on the location and extent of the bleeding and on the patient's clinical condition.The number of units of factor VIII administered is expressed in International Units (I.U.), which are related to the current WHO standard for factor VIII products. Factor VIII activity in plasma is expressed either as a percentage (relative to normal human plasma) or in International Units (relative to an International Standard for factor VIII in plasma).One International Unit (I.U.) of factor VIII activity is equivalent to that quantity of factor VIII in one ml of normal human plasma. The calculation of the required dosage of factor VIII is based on the empirical finding that 1 International Unit (I.U.) factor VIII per kg body weight raises the plasma factor VIII activity by 1.5% to 2% of normal activity. The required dosage is determined using the following formula:Required Units = Body weight (kg) x desired factor VIII rise (%) (I.U./dl) x 0.5The amount to be administered and the frequency of administration should always be oriented to the clinical effectiveness in the individual case.In the case of the following haemorrhagic events, the factor VIII activity should not fall below the given plasma activity level (in % of normal or I.U./dl) in the corresponding period.The following table can be used to guide dosing in bleeding episodes and surgery: Degree of haemorrhage/Type of surgical procedure | Factor VIII level required as % of normal (I.U./dL) | Frequency of doses (hours)/Duration of therapy (days) | Haemorrhage Early haemarthrosis, muscle bleeding or oral bleeding More extensive haemarthrosis, muscle bleeding or haematoma Life threatening haemorrhages | 20 - 40 30 - 60
60 - 100 | Repeat every 12 to 24 hours. At least 1 day, until the bleeding episode, as indicated by pain, is resolved or healing is achieved. Repeat infusion every 12 24 hours for 3 4 days or more until pain and disability are resolved. Repeat infusion every 8 24 hours until threat is resolved. | Surgery Minor, including tooth extraction Major | 30 - 60 80 - 100 (pre- and post-operative) | Every 24 hours, at least 1 day, until healing is achieved. Repeat infusion every 8 - 24 hours until adequate wound healing, then therapy for at least another 7 days to maintain a FVIII activity of 30% to 60% (I.U./dL). | During the course of treatment, appropriate determination of factor VIII levels is advised to guide the dose to be administered and the frequency of repeated infusions. In the case of major surgical interventions in particular, precise monitoring of the substitution therapy by means of coagulation analysis (plasma factor VIII activity) is indispensable. Individual patients may vary in their response to factor VIII, achieving different levels of in vivo recovery and demonstrating different half-lives.For long term prophylaxis against bleeding in patients with severe haemophilia A, the usual doses are 20 to 40 I.U. of factor VIII per kg of body weight at intervals of 2 to 3 days. In some cases, especially in younger patients, shorter dosage intervals or higher doses may be necessary.Patients should be monitored for the development of factor VIII inhibitors. If the expected factor VIII activity plasma levels are not attained, or if bleeding is not controlled with an appropriate dose, an assay should be performed to determine if a factor VIII inhibitor is present. In patients with high levels of inhibitor, factor VIII therapy may not be effective and other therapeutic options should be considered. Management of such patients should be directed by physicians with experience in the care of patients with haemophilia. See also section 4.4.Von Willebrand disease Generally, 1 I.U./kg VWF:RCo raises the circulating level of VWF:RCo by 2%. Levels of VWF:RCo of> 0.6 I.U./ml (60%) and of FVIII:C of> 0.4 I.U./ml (40%) should be achieved.Usually 40 - 80 I.U./kg of von Willebrand factor (VWF:RCo) and 20 - 40 I.U./kg of FVIII:C are recommended to achieve haemostasis.An initial dose of 80 I.U./kg of von Willebrand factor may be required, especially in patients with type 3 von Willebrand disease where maintenance of adequate levels may require greater doses than in other types of von Willebrand disease.An appropriate dose should be re-administered every 12 - 24 hours. The dose and duration of the treatment depend on the clinical status of the patient, the type and severity of bleeding, and both VWF:RCo and FVIII:C levels.When using a FVIII-containing von Willebrand factor product, the treating physician should be aware that continued treatment may cause an excessive rise in FVIII:C. After 24 - 48 hours of treatment, reduced doses and/or prolongation of the dose interval or the use of a VWF product containing a low level of FVIII should be considered.There are insufficient data to recommend the use of Alphanate® in children less than 6 years of age for the authorised indications.Method of administration Dissolve the preparation as described in section 6.6. The product should be administered via the intravenous route. The injection speed should not exceed 10 ml per minute.
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