General

Pronunciation:
an-ti-hem-oh-fill-ik ree-kom-bi-nant por-seen see-qwence

Trade Name(s)

• Obizur

Ther. Class.

hemostatic agents

none assigned

Pharm. Class.

clotting factor replacements

Indications

Treatment of bleeding episodes associated with acquired Hemophilia A.

Action

Temporarily replaces deficient levels of factor VIII.

Therapeutic Effect(s):

Hemostasis in patients with acquired Hemophilia A.

Pharmacokinetics

Vary from patient to patient

Absorption: IV administration results in complete bioavailability.

Distribution: Unknown.

Metabolism and Excretion: Used up in the hemostatic process.

Half-life: Unknown.

TIME/ACTION PROFILE (effect on factor VIII levels)

Contraindication/Precautions

Contraindicated in:

• Life-threatening hypersensitivity reactions to this product or any of its components (including hamster protein).

Use Cautiously in:

• OB:  Use during pregnancy only if clinically needed;
• Lactation: Use cautiously if breastfeeding;
• Pedi:  Safe and effective use in children has not been established.

Adverse Reactions/Side Effects

Misc: development of inhibitory antibodies to porcine factor VIII, allergic reactions including ANAPHYLAXIS

* CAPITALS indicate life-threatening.
Underline indicate most frequent.

Interactions

Drug-Drug

Bleeding may be ↑ by aspirin, NSAIDs, antiplatelet agents, anticoagulants and SSRIs.

Route/Dosage

IV (Adults): Initial dose: 200 units/kg; further doses every 4–12 hr are titrated and based on clinical response and factor VIII recovery levels.

Availability

Lyophilized powder for IV solution (requires reconstitution): 500 units/single-use vial

Assessment

• Monitor for signs and symptoms of hypersensitivity reactions (angioedema, chest-tightness, dyspnea, hypotension, wheezing, urticaria, pruritus). If symptoms occur, discontinue administration and provide symptomatic treatment.

Lab Test Considerations:

Perform one-stage clotting assay to confirm that adequate factor VIII levels have been achieved and maintained. Monitor factor VIII activity 30 minutes and 3 hours after initial dose. Monitor factor VIII activity 30 minutes after subsequent doses.  For superficial muscle bleeding with no neurovascular compromise, and joint bleeding,  Factor VIII of 50–100 units/dL or % of normal are required.   For moderate to severe intramuscular bleeding, retroperitoneal, gastrointestinal, or intracranial bleeding,  use 100–200 units/dL or % normal to treat an acute bleed. Administer 50–100 units/dL or % of normal after acute bleed if more is required.

• Monitor development of inhibitory antibodies with Nijmegen Bethesda inhibitor assay if expected plasma factor VIII activity levels are not attained or if bleeding is not controlled with the expected dose. Use Bethesda Units (BU) to report inhibitor levels.

Implementation

• IV Push:  Reconstitute by bringing solution to room temperature. Follow manufacturer's instructions for reconstitution. Inject all diluent from syringe into vial; gently swirl without removing syringe until completely dissolved. Use within 3 hrs of reconstitution if stored at room temperature. Solution is clear and colorless; do not administer solutions that are discolored or contain particulate matter. Once all vials are reconstituted, connect large syringe to vial adapter and withdraw all solution. Repeat until total volume to be administered is reached. Discard unused reconstituted solution.
• Rate: Inject 1–2 mL/min.

Patient/Family Teaching

• Explain rationale for medication to patient.
• Instruct patient to notify health care professional of adverse reactions or problems following administration.
• Advise female patient to notify health care professional if pregnancy is planned or suspected or if breastfeeding.

Evaluation/Desired Outcomes

Hemostasis in patients with acquired Hemophilia A. If the plasma factor VIII level fails to increase as expected, or if bleeding is not controlled after OBIZUR administration, suspect the presence of an anti-porcine factor VIII antibody. If such inhibitory antibodies to anti-porcine factor VIII are suspected and there is a lack of clinical response, consider other therapeutic options.