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Pronunciation |
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(an
tee hee moe FIL ik FAK tor HYU
man) |
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U.S. Brand
Names |
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Hemofil® M; Humate-P®;
Koate®-HP; Koate®-HS; Monoclate-P®;
Profilate® OSD; Profilate®
SD |
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Generic
Available |
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Yes |
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Synonyms |
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AHF; Factor VIII |
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Pharmacological Index |
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Antihemophilic Agent; Blood Product Derivative |
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Use |
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Management of hemophilia A in patients whom a deficiency in factor VIII has
been demonstrated. Can be of significant therapeutic value in patients with
acquired factor VII inhibitors not exceeding 10 Bethesda units/mL.
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Pregnancy Risk
Factor |
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C |
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Contraindications |
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Hypersensitivity to mouse protein (Monoclate-P®;
Hemofil® M, Method M, Monoclonal Purified) and
Antihemophilic Factor (Human); Method M, Monoclonal Purified contain trace
amounts of mouse protein |
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Warnings/Precautions |
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Risk of viral transmission is not totally eradicated. Risk of hepatitis:
Because antihemophilic factor is prepared for pooled plasma, it may contain the
causative agent of viral hepatitis. Antihemophilic factor contains trace amounts
of blood groups A and B isohemagglutinins; when large or frequently repeated
doses are given to individuals with blood groups A, B, and AB, the patient
should be monitored for signs of progressive anemia and the possibility of
intravascular hemolysis should be considered. |
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Adverse
Reactions |
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<1%: Flushing, tachycardia, headache, nausea, vomiting, paresthesia,
allergic vasomotor reactions, tightness in neck or chest |
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Overdosage/Toxicology |
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Intravascular hemolysis |
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Stability |
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Dried concentrate should be refrigerated (2°C to
8°C/36°F to
46°F) but may be stored at room temperature for up to 6
months depending upon specific product; if refrigerated, the dried concentrate
and diluent should be warmed to room temperature before reconstitution; gently
agitate or rotate vial after adding diluent, do not shake vigorously; do
not refrigerate after reconstitution, a precipitation may occur; Method M,
monoclonal purified products should be administered within 1 hour after
reconstitution |
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Mechanism of
Action |
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Protein (factor VIII) in normal plasma which is 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 |
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Pharmacodynamics/Kinetics |
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Distribution: Does not readily cross the placenta
Half-life, biphasic: 4-24 hours with a mean of 12 hours (biphasic: 12 hours
is usually used for dosing interval estimates) |
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Usual Dosage |
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I.V.: Individualize dosage based on coagulation studies performed prior to
and during treatment at regular intervals; 1 AHF unit is the activity present in
1 mL of normal pooled human plasma; dosage should be adjusted to actual vial
size currently stocked in the pharmacy.
Surgery patients: The factor VIII level should be raised to approximately
100% by giving a preoperative dose of 50 international units/kg, to maintain
hemostatic levels, repeat infusions may be necessary every 6-12 hours initially
and for a total of 10-14 days until healing is complete
Formula to approximate percentage increase in plasma antihemophilic
factor:
Units required = desired level increase (desired level - actual level) x
plasma volume (mL)
Total blood volume (mL blood/kg) = 70 mL/kg (adults); 80 mL/kg (children)
Plasma volume = total blood volume (mL) x [1 - Hct (in decimals)]
Example: For a 70 kg adult with a Hct = 40%: plasma volume = [70 kg x 70
mL/kg] x [1 - 0.4] = 2940 mL
To calculate number of units of factor VIII needed to increase level to
desired range (highly individualized and dependent on patient's condition):
Number of units = desired level increase [desired level - actual level] x
plasma volume (in mL)
Example: For a 100% level in the above patient who has an actual level of 20%
the number of units needed = [1 (for a 100% level) - 0.2] x 2940 mL = 2352 units
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Monitoring
Parameters |
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Heart rate (before and during I.V. administration); antihemophilic factor
levels prior to and during treatment; in patients with circulating inhibitors,
the inhibitor level should be monitored |
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Reference Range |
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Average normal antihemophilic factor plasma activity ranges 50% to 150%
Level to prevent spontaneous hemorrhage: 5%
Required peak postinfusion AHF activity in blood (as % of normal or units/dL
plasma):
Early hemarthrosis or muscle bleed or oral bleed: 20% to 40%
More extensive hemarthrosis, muscle bleed, or hematoma: 30% to 60%
Life-threatening bleeds, such as head injury, throat bleed, severe abdominal
pain
Minor surgery, including tooth extraction: 60% to 80%
Major surgery: 80% to 100% (pre- and postoperative) |
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Mental Health: Effects
on Mental Status |
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None reported |
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Mental Health:
Effects on Psychiatric
Treatment |
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None reported |
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Dental Health: Local
Anesthetic/Vasoconstrictor
Precautions |
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No information available to require special precautions |
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Dental Health:
Effects on Dental Treatment |
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No effects or complications reported |
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Patient
Information |
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This medication can only be given I.V. Report sudden onset headache, rash,
chest or back pain, or respiratory difficulties. Future safety: Wear some
identification that you have a hemophilic condition.
Pregnancy/breast-feeding precautions: Inform prescriber if you are or intend
to be pregnant. Consult prescriber if breast-feeding. |
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Nursing
Implications |
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Reduce rate of administration or temporarily discontinue if patient becomes
tachycardiac |
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Dosage Forms |
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Injection: 10 mL, 20 mL, 30 mL |
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References |
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Berntorp E,
"Impact of Replacement Therapy on the Evolution of HIV Infection in Hemophiliacs,"
Thromb Haemost, 1994, 71(6):678-83.
Berntorp E,
"Plasma Product Treatment in Various Types of von Willebrand Disease,"
Haemostasis, 1994, 24(5):287-97.
Lusher JM, "Transfusion Therapy in Congenital Coagulopathies," Hematol
Oncol Clin North Am, 1994, 8(6):1167-80.
Manucci PM, "Impact of Recombinant Factor VIII on Hemophilia Care," Vox
Sang, 1994, 67(Suppl 3):49-52.
Peterson CW, "Treating Hemophilia," Am Pharm, 1994, NS34(8):57-67.
Scharrer I, Vigh T, and Aygoren-Purun E,
"Experience With Haemate P in von Willebrand Disease," Haemostasis, 1994,
24(5):298-303. |
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