Optivate

INJECTION, POWDER, FOR SOLUTION

**4.2 Posology and method of administration** Treatment should be initiated under the supervision of a physician experienced in the treatment of haemophilia. 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 the patient's clinical condition. **Posology** _On demand treatment_ 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 an 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 dosage of factor VIII is based on the empirical finding that 1 international unit factor VIII per kg body weight raises the plasma factor VIII activity by 2.2%–2.7% of normal activity (2.2–2.7 international units/dl). The required dosage is determined using the following formula:  The amount to be administered and the frequency of administration should always be orientated 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; international unit/dl) in the corresponding period. The following table can be used to guide dosing in bleeding episodes and surgery:  _Prophylaxis_ For long term prophylaxis against bleeding in adult patients with severe haemophilia A, the usual doses are 20 to 40 international units of factor VIII per kg body weight at intervals of 2 to 3 days. In some patients, shorter dosage intervals or higher doses may be necessary. 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. _Paediatric patients_ Optivate is indicated for on demand use in children, including those less than 6 years of age. There are insufficient data to recommend the use of Optivate in children less than 6 years of age for routine prophylaxis. In the clinical study in children less than 6 years of age with severe haemophilia A, the median dose to treat a bleed was 25.8 international units/kg (range 17.1 to 58.2 international units/kg) but the majority of bleeds were categorised as minor. The target factor VIII concentrations for different types of bleeds in the table above should also be applied to children and adolescents. _Children over 6 years of age_ There are very limited data on the use of Optivate in children aged 6 to 12 years. 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 – _please refer to the Product Insert/Patient Information Leaflet published on HSA for the full drug information_. **Method of administration** Dissolve the preparation as described in 6.6 – _please refer to the Product Insert/Patient Information Leaflet published on HSA for the full drug information_. The product should be administered via the intravenous route at a rate not exceeding 3 ml per minute (note that increasing the rate of administration may result in side effects). If it is necessary to receive more than one vial, the contents of all the vials may be drawn up into a syringe of appropriate size. A separate sterile filter needle/Mix2Vial should be used for each vial because sterile filter needles/Mix2Vials are intended to filter the contents of a single vial of Optivate.