Treatment should be initiated under the supervision of a physician experienced in the treatment of haemophilia.
Posology
The number of units of factor VIII administered is expressed in International Units (IU), 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 the International Standard for factor VIII in plasma). One International Unit (IU) of factor VIII activity is equivalent to that quantity of factor VIII in one ml of normal human plasma. The calculation of the required dose of factor VIII is based on the empirical finding that 1 International Unit (IU) factor VIII per kg body weight raises the plasma factor VIII activity by 1.5% to 2.5% of normal activity. The required dose is determined using the following formulae:

On demand treatment
The dose, frequency and duration of the substitution therapy must be individualised according to the patient's needs (weight, severity of disorder of the haemostatic function, the site and extent of the bleeding, the presence of inhibitors, and the factor VIII level desired).
The following table provides a guide for factor VIII minimum blood levels. In the case of the haemorrhagic events listed, the factor VIII activity should not fall below the given level (in % of normal) in the corresponding period:
Degree of haemorrhage/Type of surgical procedure
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Factor VIII level required (%) (IU/dl)
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Frequency of doses (hours)/Duration of therapy (days)
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Haemorrhage
Early haemarthrosis, muscle bleed or oral bleed
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20 - 40
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Repeat every 12 to 24 hours. At least 1 day, until the bleeding episode as indicated by pain is resolved or healing is achieved.
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More extensive haemarthrosis, muscle bleed or haematoma
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30 - 60
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Repeat infusion every 12 - 24 hours for 3 - 4 days or more until pain and disability are resolved.
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Life threatening bleeds such as intracranial bleed, throat bleed, severe abdominal bleed
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60 - 100
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Repeat infusion every 8 to 24 hours until threat is resolved
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Surgery
Minor
including tooth extraction
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30 - 60
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Every 24 hours, at least 1 day, until healing is achieved.
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Major
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80 - 100
(pre- and postoperative)
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a) By bolus infusions
Repeat infusion every 8 - 24 hours until adequate wound healing occurs, then continue with therapy for at least another 7 days to maintain a factor VIII activity of 30% to 60%
b) By continuous infusion
Raise factor VIII activity pre-surgery with an initial bolus infusion and immediately follow with continuous infusion (in IU/Kg/h) adjusting according to patient's daily clearance and desired factor VIII levels for at least 7 days.
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The amount to be administered and the frequency of administration should always be adapted according to the clinical effectiveness in the individual case. Under certain circumstances larger amounts than those calculated may be required, especially in the case of the initial dose.
During the course of treatment, appropriate determination of factor VIII levels is advised in order to guide the dose to be administered and the frequency at which to repeat the 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.
Continuous Infusion
It has been shown in a clinical study performed with adult haemophilia A patients who undergo a major surgery that KOGENATE Bayer can be used for continuous infusion in surgeries (pre-, during and postoperative). In this study heparin was used to prevent thrombophlebitis at the infusion site as with any other long term intravenous infusions. For the calculation of the initial infusion rate, clearance can be obtained by performing a pre-surgery decay curve, or by starting from an average population value (3.0-3.5 ml/h/kg) and then adjust accordingly.
Infusion rate (in IU/kg/h) = Clearance (in ml/h/kg) x desired factor VIII level (in IU/ml)
For continuous infusion, clinical and in vitro stability has been demonstrated using ambulatory pumps with a PVC reservoir. KOGENATE Bayer contains low level of polysorbate-80 as an excipient, which is known to increase the rate of di-(2-ethylhexyl)phthalate (DEHP) extraction from polyvinyl chloride (PVC) materials. This should be considered for a continuous infusion administration.
Prophylaxis
For long term prophylaxis against bleeding in patients with severe haemophilia A, the usual doses are 20 to 40 IU of KOGENATE Bayer per kg body weight should be given at intervals of 2 to 3 days. In some cases, especially in younger patients, shorter dose intervals or higher doses may be necessary.
Paediatric population
Data have been obtained from clinical studies in 61 children under 6 years of age and non-interventional studies in children of all ages.
Patients with inhibitors
Patients should be monitored for the development of factor VIII inhibitors. If the expected plasma factor VIII activity 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. If the inhibitor is present at levels less than 10 Bethesda Units (BU) per ml, administration of additional recombinant coagulation factor VIII may neutralise the inhibitor and permit continued clinically effective therapy with KOGENATE Bayer. However, in the presence of an inhibitor the doses required are variable and must be adjusted according to clinical response and monitoring of plasma factor VIII activity. In patients with inhibitor titres above 10 BU or with high anamnestic response, the use of (activated) prothrombin complex concentrate (PCC) or recombinant activated factor VII (rFVIIa) preparations has to be considered. These therapies should be directed by physicians with experience in the care of patients with haemophilia.
Method of administration
For intravenous use.
KOGENATE Bayer should be injected intravenously over several minutes. The rate of administration should be determined by the patient's comfort level (maximal rate of infusion: 2 ml/min).
Continuous infusion
KOGENATE Bayer can be infused by continuous infusion. The infusion rate should be calculated based on the clearance and the desired FVIII level.
Example: for a 75 kg patient with a clearance of 3 ml/h/kg, the initial infusion rate would be 3 IU/h/kg to achieve a FVIII level of 100%. For calculation of ml/hour, multiply infusion rate in IU/h/kg by kg bw/concentration of solution (IU/ml).
Example for calculation of infusion rate for continuous infusion after initial bolus injection
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Desired plasma
FVIII level
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Infusion rate
IU/h/kg
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Infusion rate for 75 kg patient
ml/h
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Clearance: 3 ml/h/kg
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|
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Concentrations of rFVIII solution
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100 IU/ml
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200 IU/ml
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400 IU/ml
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100 % (1 IU/ml)
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3.0
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2.25
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1.125
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0.56
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60 % (0.6 IU/ml)
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1.8
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1.35
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0.68
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0.34
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40 % (0.4 IU/ml)
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1.2
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0.9
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0.45
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0.225
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Higher infusion rates may be required in conditions with accelerated clearance during major bleedings or extensive tissue damage during surgical interventions.
After the initial 24 hours of continuous infusion, the clearance should be recalculated every day using the steady state equation with the measured FVIII level and the rate of infusion using the following equation:
clearance = infusion rate/actual FVIII level.
During continuous infusion, infusion bags should be changed every 24 hours.
For instructions on reconstitution of the medicinal product before administration, see section 6.6 and the package leaflet.
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