Antihemophilic Factor (Recombinant), Porcine Sequence
Class: Hemostatics
VA Class: BL500
Brands: Obizur
Introduction
Biosynthetic (recombinant DNA origin) preparation of porcine blood coagulation factor VIII.
Uses for Antihemophilic Factor (Recombinant), Porcine Sequence
Acquired Hemophilia A
Treatment and prevention of bleeding episodes in patients with acquired hemophilia A, a condition caused by the development of autoantibodies (inhibitors) to antihemophilic factor (blood coagulation factor VIII).
Because of reduced cross-reactivity (about 5–10%) with human factor VIII inhibitors, may be useful in situations where human antihemophilic factor concentrates are ineffective.
Designated an orphan drug by FDA for treatment and prevention of bleeding in patients with inhibitor antibodies to human coagulation factor VIII.
Manufacturer states that safety and efficacy not established in patients with baseline anti-porcine factor VIII inhibitor titers >20 Bethesda Units.
Manufacturer states that drug not indicated for treatment of patients with congenital hemophilia A or von Willebrand disease.
Antihemophilic Factor (Recombinant), Porcine Sequence Dosage and Administration
General
Individualize dosage and duration of therapy based on location and severity of bleeding, target factor VIII levels, and patient's clinical and pharmacokinetic (e.g., in-vivo recovery, half-life) response.
Monitor factor VIII activity (by the one-stage clotting assay) after each dose is given to ensure that adequate levels of factor VIII are attained and maintained. (See Laboratory Monitoring under Cautions.) Careful control of dose is especially important in cases of life-threatening bleeding or major surgery.
If administered dose is ineffective in achieving expected factor VIII levels or bleeding not controlled, consider possibility that inhibitors may have developed. (See Development of Inhibitors to Porcine Factor VIII under Cautions.)
Administration
IV Administration
Administer by slow IV injection or slow IV infusion. (See Rate of Administration under Dosage and Administration.)
Reconstitution
Reconstitute lyophilized powder with manufacturer-supplied prefilled diluent syringe. May require reconstitution of more than one vial to obtain required dose.
Prior to reconstitution, allow drug vial and diluent to warm to room temperature. After addition of diluent, gently swirl vial until powder is completely dissolved. Resultant solution should be clear and colorless; discard if particulate matter or discoloration observed.
Administer within 3 hours after reconstitution.
Do not administer reconstituted solution in the same tubing or container with other drugs.
Consult manufacturer's labeling for specific instructions on reconstitution and preparation.
Rate of Administration
Administer at a rate of 1–2 mL per minute.
Dosage
Dosage and potency expressed in terms of international units (IU, units) of antihemophilic factor activity. Potency...
