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Antihemophilic Factor (Recombinant [Porcine Sequence])

Pronunciation

(an tee hee moe FIL ik FAK tor ree KOM be nant POR sine SEE kwens)

Index Terms

  • AHF (Recombinant [Porcine Sequence])
  • Factor VIII (Recombinant [Porcine Sequence])
  • pFVIII
  • rAHF
  • rpFVIII

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Solution Reconstituted, Intravenous:

Obizur: 500 units (1 ea) [contains mouse (murine) and/or hamster protein, polysorbate 80]

Brand Names: U.S.

  • Obizur

Pharmacologic Category

  • Antihemophilic Agent

Pharmacology

Factor VIII replacement, necessary for clot formation and maintenance of hemostasis, activates factor X in conjunction with activated factor IX. Activated factor X converts prothrombin to thrombin, which converts fibrinogen to fibrin, and with factor XIII forms a stable clot.

Use: Labeled Indications

Acquired hemophilia A: Treatment of bleeding episodes in adults with acquired hemophilia A

Limitations of use: Not indicated for the treatment of congenital hemophilia A or von Willebrand disease; safety and efficacy of has not been established in patients with baseline anti- porcine factor VIII inhibitor titer >20 BU.

Contraindications

Life-threatening hypersensitivity reactions to antihemophilic factor or any component of the formulation (including traces of hamster proteins).

Dosing: Adult

Acquired hemophilia A: IV: Note: Dose, dosing frequency, and duration based on location and severity of bleeding, target factor VIII levels, and clinical condition of the patient. Plasma levels of factor VIII should not exceed 200% of normal or 200 units/dL.

Minor to moderate hemorrhage: 200 units/kg initially to achieve factor VIII plasma level 50% to 100% of normal; titrate subsequent doses to maintain recommended factor VIII trough levels and individual clinical response; dose every 4 to 12 hours (frequency may be adjusted based on clinical response/factor VIII levels).

Major hemorrhage: 200 units/kg initially to achieve factor VIII plasma level 100% to 200% (for acute bleed) or 50% to 100% (after acute bleed is controlled, if required) of normal; titrate subsequent doses to maintain recommended factor VIII trough levels and individual clinical response; dose every 4 to 12 hours (frequency may be adjusted based on clinical response/factor VIII levels).

Dosing: Geriatric

Refer to adult dosing.

Dosing: Renal Impairment

There are no dosage adjustments provided in the manufacturer’s labeling.

Dosing: Hepatic Impairment

There are no dosage adjustments provided in the manufacturer’s labeling.

Reconstitution

Allow vial and diluent to warm to room temperature before reconstitution. Gently swirl vial in a circular motion after adding diluent until dissolved.

Administration

IV: Administer IV at a rate of 1 to 2 mL/minute. Do not administer in the same tubing or container with other medicinal products.

Storage

Store refrigerated at 2°C to 8°C (36°F to 46°F). Do not freeze. Store the original package to protect from light. Use within 3 hours after reconstitution; discard any unused solution if not used within 3 hours after reconstitution.

Drug Interactions

There are no known significant interactions.

Adverse Reactions

>10%: Immunologic: Antibody development (26%)

<1% (Limited to important or life-threatening): Hypersensitivity reaction

Warnings/Precautions

Concerns related to adverse effects:

• Antibody formation: Formation of antiporcine factor VIII antibodies has occurred; monitor patients for the development of antibodies. Suspect an antiporcine factor VIII antibody if the plasma factor VIII level does not increase as expected or if bleeding is not controlled after administration. If inhibitory antibodies are suspected and there is a lack of clinical response, consider other therapy.

• Hypersensitivity reactions: May occur; discontinue immediately if allergic or anaphylactic-type reactions occur.

Dosage form specific issues:

• Hamster protein: May contain trace amounts of hamster proteins.

• Polysorbate 80: Some dosage forms may contain polysorbate 80 (also known as Tweens). Hypersensitivity reactions, usually a delayed reaction, have been reported following exposure to pharmaceutical products containing polysorbate 80 in certain individuals (Isaksson, 2002; Lucente 2000; Shelley, 1995). Thrombocytopenia, ascites, pulmonary deterioration, and renal and hepatic failure have been reported in premature neonates after receiving parenteral products containing polysorbate 80 (Alade, 1986; CDC, 1984). See manufacturer’s labeling.

• Sucrose: May contain sucrose.

Other warnings/precautions:

• Dose requirements: The dosage requirement will vary in patients with factor VIII inhibitors; optimal treatment should be determined by clinical response.

Monitoring Parameters

Heart rate and blood pressure (before and during IV administration); plasma factor VIII activity prior to and during treatment (30 minutes and 3 hours after initial dose; 30 minutes after subsequent doses); development of factor VIII inhibitors; signs of bleeding; hemoglobin, hematocrit.

Pregnancy Risk Factor

C

Pregnancy Considerations

Animal reproduction studies have not been conducted.

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Have patient report immediately to prescriber dizziness, passing out, severe loss of strength and energy, nausea, vomiting, agitation, burning or numbness feeling, or shortness of breath (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.

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