factor VIII (redirected from Factor 8)

factor VIII

n.

A factor in the clotting of blood, a deficiency of which is associated with hemophilia A. Also called antihemophilic factor, antihemophilic globulin, antihemophilic globulin A, proserum prothrombin conversion accelerator.

---

Factor VIII

A protein involved in blood clotting that requires vWF for stability and long-term survival in the bloodstream.

Mentioned in: Von Willebrand Disease

---

factor VIII,

a coagulation factor present in normal plasma but deficient in the blood of persons with hemophilia A. It is a macromolecular complex composed of two separate entities, one of which, when deficient, results in hemophilia A, and the other, when deficient, results in von Willebrand's disease. See also factor XI.

---

factor(s),

n a constituent, element, cause, or agent that influences a process or system; a gene; a dietary substance.

factor I (fibrinogen, profibrin),

n See fibrinogen.

factor II (prothrombin, component A, prothrombase, prothrombin B, thrombogen, thrombozyme),

n considered the only essential precursor of thrombin.

factor III (thromboplastin [tissue], thrombokinase, cytozyme platelet], thrombokinin [blood], thromboplastic protein),

n See thromboplastin.

factor IV (calcium, Ca),

n ionized and/or bound calcium, generally required for the coagulation of blood, although some early phases of coagulation and the thrombin-fibrinogen reaction can take place without calcium.

factor V (labile factor, proaccelerin, accelerin, acceleration factor, cofactor of thromboplastin, component A of prothrombin, plasma ac-globulin, plasma prothrombin conversion factor [PPCF], prothrombinase, prothrombin accelerator, prothrombin conversion accelerator I, thrombogen, thrombogene, proaccelerinaccelerin system),

n a factor apparently necessary for the formation of a prothrombin-converting substance in blood and tissue extracts–i.e., intrinsic and extrinsic prothrombin activators. A deficiency results in parahemophilia (hypoproaccelerinemia).

factor VI,

n term formerly used to indicate an intermediate product in the formation of thromboplastin and also used synonymously with accelerin and activated factor V. It has no designation at present.

factor VII (stable factor, serum prothrombin conversion accelerator SPCA], proconvertin, autoprothrombin I, cofactor V, component B of prothrombin,

cothromboplastin, kappa factor, precusor of serum prothrombin conversion accelerator [pro-SPCA], prothrombin conversion factor, prothrombin converting factor, prothrombin conversion accelerator II, proconvertinconvertin system, prothrombinogen, serozyme, stable factor),
n a factor that accelerates the conversion of prothrombin to thrombin in the presence of factors III, IV, and V; a serum factor necessary for the formation of extrinsic prothrombin activator.

factor VII deficiency,

n a deficiency associated with a lack of vitamin K. A deficiency may be congenital, or it may be acquired in liver disease, or from prothrombinopenic agents used in anticoagulation therapy; it results in a prolonged (quantitative) one-stage prothrombin time test.

factor VIII (antihemophilic factor [AHF], antihemophilic globulin, antihemophilic globulin A, antihemophilic factor A, plasma thromboplastin factor [PTF], plasmokinin, platelet cofactor I, prothrombokinase, thrombocatalysin, thrombocytolysin, thrombokatilysin, thromboplastic plasma component [TPC], thromboplastinogen),

n a factor essential for the formation of blood thromboplastin. A deficiency results in classic hemophilia (hemophilia A); the clotting time is prolonged, and thromboplastin and prothrombin conversion is diminished.

factor IX (Christmas factor, plasma thromboplastin component [PTC], antihemophilic factor B, antihemophilic globulin B, autoprothrombin II, beta prothromboplastin, plasma factor X, plasma thromboplastin factor B PTF-B], platelet cofactor II),

n a factor that is active in the formation of intrinsic blood thromboplastin. A deficiency results in Christmas disease (hemophilia B), which is caused by a decrease in the amount of thromboplastin formed.

factor X (Stuart-Prower factor, Stuart factor, Prower factor),

n a factor influencing the yield of intrinsic (plasma) thromboplastin. A deficiency results in a prolonged one-stage prothrombin time. Brain tissue or Russell's viper venom are used to test for thromboplastin deficiency.

factor XI (plasma thromboplastin antecedent [PTA], antihemophilic factor C, PTA factor, plasma thromboplastin factor C [PTF-C]),

n a factor related to intrinsic (plasma) thromboplastin activation, which occurs when blood is exposed to a foreign surface.

factor XI deficiency,

n a deficiency caused by an autosomal recessive gene resulting in a hemorrhagic tendency. See also hemophilia C.

factor XII (Hageman factor, antihemophilic factor D, clot-promoting factor, fifth plasma thromboplastin precursor, glass factor),

n a factor the absence of which results in a long clotting time and abnormal prothrombin consumption and thromboplastin generation tests when tests are carried out in glass tubes. No abnormal bleeding tendency occurs with a deficiency of the factor.

factor XIII,

n a coagulation factor present in normal plasma that acts with calcium to produce an insoluble fibrin clot. Also called
fibrinase or
fibrin stabilizing factor.

factor XIII deficiency,

n a deficiency caused by a deficiency of vitamin E.

factor, acceleration,

n See factor V.

factor, antihemophilic (AHF),

n See factor VIII.

factor, antihemophilic A,

n See factor VIII.

factor, antihemophilic B,

n See factor IX.

factor, antihemophilic C,

n See factor XI.

factor, antihemophilic D,

n See factor XII.

factor, antipernicious,

n See vitamin B₁₂.

factor, C (contact factor, contact activation product, third thromboplastic factor),

n a coagulation accelerator product formed by the interaction of active factor XII and factor XI.

factor, Castle's intrinsic (intrinsic factor),

n.pr a factor produced by the gastric mucosa and possibly the duodenal mucosa, and considered to be responsible for the absorption of vitamin B₁₂. See also anemia, pernicious.

factor, Christmas,

n See factor IX.

factor, clot-promoting,

n See factor XII.

factor, clotting,

n the “trace” proteins (excluding calcium) present in normal blood in such small amounts (except fibrinogen) that their presence is usually established by deductive reasoning and by genetic and biochemical characteristics. They are associated with thromboplastic activity and the conversion of prothrombin to thrombin.

factor, contact,

n See factor C.

factor, environmental,

n the local conditions that modify tissue response (e.g., narrow interdental spaces, saddle areas, attachment of frenula, oblique ridges).

factor, erythrocyte-maturation (EMF),

n See vitamin B complex.

factor, etiologic,

n the element or influence that can be assigned as the cause or reason for a disease or lesion.

factor, extrinsic,

n See vitamin B complex.

factor, familial,

n a characteristic derived through heredity.

factor, glass,

n See factor XII.

factor, glucocorticoid,

n See hormone, “S.”

factor, Hageman,

n See factor XII.

factor, Hr,

n blood factors that are reciprocally related to the Rh factors. They are present in agglutinogens when the corresponding Rh factor is absent from the gene.

factor, hyperglycemic,

n See glucagon.

factor, hyperglycemic-glycogenolytic,

n See glucagon.

factor, intrinsic,

n See factor, Castle's intrinsic.

factor, kappa,

n See factor VII.

factor, labile,

n See factor V.

factor, local,

n the limited factors that include dental plaque, bacterial toxins and irritants, calculus, food impaction, and other surface and locally placed irritants that are capable of injuring the periodontium.

factor, pellagra-preventive,

n See acid, nicotinic.

factor, plasma prothrombin conversion (PPCF),

n See factor V.

factor, plasma thromboplastin (PTF),

n the substances with thromboplastic activity contributed by the plasma. Included are the antihemophilic factor, Christmas factor, plasma thromboplastin antecedent, and Hageman factor. See also factor VIII.

factor, plasma thromboplastin, A (PTF-A),

n See factor VIII.

factor, plasma thromboplastin, B (PTF-B),

n See factor IX.

factor, plasma thromboplastin, C (PTF-C),

n See factor XI.

factor, plasma thromboplastin, D (PTF-D),

n this factor is considered by some to be a fourth plasma substance with thromboplastic activity; not well characterized.

factor, plasma, X,

n See factor IX.

factor, platelet,

n a substance on or in the surface of blood platelet necessary for coagulation in the absence of extravascular thromboplastic substances.

factor, platelet, 1,

n either factor V or a factor with factor V activity; absorbed on platelets and accelerates conversion of prothrombin to thrombin.

factor, platelet, 2,

n a substance that accelerates the conversion of fibrinogen to fibrin.

factor, platelet, 3,

n a substance associated with thromboplastin generation activity.

factor, platelet, 4,

n an antiheparin factor.

factor, prothrombin conversion,

n See factor VII.

factor, prothrombin-converting,

n See factor VII.

factor, Prower,

n.pr See factor X.

factor, psychosomatic,

n the psychic, mental, or emotional factors that play a role in determining the initiation, course, and extent of a physical process, either directly or indirectly. Psychosomatic factors have been implicated in bruxism, clenching, and other oral habits.

factor, PTA (plasma thromboplastin antecedent factor),

n See factor XI.

factor, reparative,

n the ability of the tissues to heal or regenerate when they have been subjected to injury or disease.

factor, Rh,

n the agglutinogens of red blood cells responsible for isoimmune reactions such as occur in erythroblastosis fetalis and incompatible blood transfusions.

factor, spreading,

n an enzyme that increases the permeability of ground substance.

factor, stable,

n See factor VII.

factor, Stuart,

n.pr See factor X.

factor, Stuart-Prower,

n.pr See factor X.

factor, third thromboplastic,

n See factor C.

---

antihemophilic factor (AHF, factor VIII)

Alphanate, Hemofil M, Koate-DVI, Kogenate FS, Monarc-M, Monoclate-P, Recombinate, ReFacto

Pharmacologic class: Hemostatic

Therapeutic class: Antihemophilic

Pregnancy risk category C

FDA Boxed Warning

• Drug is made from human plasma and may contain infectious agents. Plasma donor screening, testing, and inactivation or removal methods reduce this risk.

Action

Promotes conversion of prothrombin to thrombin (necessary for hemostasis and blood clotting). Also replaces missing or deficient clotting factors, thereby controlling or preventing bleeding.

Availability

I.V. injection: 250, 500, 1,000, or 1,500 international units/vial in numerous preparations

⊘Indications and dosages

➣ Spontaneous hemorrhage in patients with hemophilia A (factor VIII deficiency)

Adults and children: Dosage is highly individualized, calculated as follows: AHF required (international units) equals weight (kg) multiplied by desired factor VIII increase (% of normal) multiplied by 0.5.

To control bleeding, desired factor VIII level is 20% to 40% of normal for minor hemorrhage; 30% to 60% of normal for moderate hemorrhage; or 60% to 100% of normal for severe hemorrhage. To prevent spontaneous hemorrhage, desired factor VIII level is 5% of normal.

Contraindications

• Hypersensitivity to drug or to mouse, hamster, or bovine protein

Precautions

Use cautiously in:
• hepatic disease
• blood types A, B, and AB
• patients receiving factor VIII inhibitors
• pregnant patients
• neonates and infants.

Administration

• Before giving, verify that patient has no history of hypersensitivity to drug or to mouse, hamster, or bovine protein.
• Follow prescriber's instructions regarding hepatitis B prophylaxis before starting therapy.
• Refrigerate concentrate until ready to reconstitute drug; then warm to room temperature before mixing.
• Roll bottle gently between hands until drug is well-mixed.
• Give a single dose over 5 to 10 minutes at rate of 2 to 10 ml/minute, as appropriate.
• After drug is reconstituted, don't refrigerate, shake, or store near heat.
• Don't mix with other I.V. solutions.
• Use plastic (not glass) syringe and filter.

Route	Onset	Peak	Duration
I.V.	Immediate	1-2 hr	Unknown

Adverse reactions

CNS: headache; lethargy; fatigue; dizziness; jitteriness; drowsiness; depersonalization; tingling in arms, ears, and face

CV: chest tightness, angina pectoris, tachycardia, slight hypotension, thrombosis

EENT: blurred or abnormal vision, eye disorder, otitis media, epistaxis, rhinitis, sore throat

GI: nausea, vomiting, diarrhea, constipation, stomachache, abdominal pain, gastroenteritis, anorexia

Hematologic: forehead bruises, increased bleeding tendency, thrombocytopenia, hemolytic anemia, intravascular hemolysis, hyperfibrinogenemia

Hepatic: hepatitis B transmission

Musculoskeletal: myalgia, muscle weakness, bone pain, finger pain

Respiratory: dyspnea, coughing, wheezing, bronchospasm

Skin: rash, acne, flushing, diaphoresis, urticaria

Other: taste changes, allergic reaction, fever, chills, cold feet, cold sensations, infected hematoma, stinging at injection site, anaphylaxis, human immunodeficiency virus transmission

Interactions

Drug-diagnostic tests. Bilirubin, creatine kinase: increased levels

Hemoglobin, platelets: decreased values

Patient monitoring

☞ Monitor for signs and symptoms of anaphylaxis and hemolysis.
☞ Watch for bleeding tendency and hemorrhaging.
• Check vital signs regularly.
• Monitor CBC and coagulation studies.
☞ Assess for severe headache (may indicate intracranial hemorrhage).

Patient teaching

☞ Tell patient to immediately report signs and symptoms of allergic response or bleeding tendency.
• Caution patient not to use aspirin during therapy.
• Instruct patient to contact prescriber if drug becomes less effective.
• Tell patient to report signs or symptoms of hepatitis B.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, alertness, and vision.
• Advise patient to minimize GI upset by eating small, frequent servings of food and drinking plenty of fluids.
• Notify patient that he'll undergo regular blood testing during therapy.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the tests mentioned above.

---

factor VIII

Anti-hemophilic factor Hematology A heterotrimeric coagulation factor that forms a complex with factor IX, platelets, and calcium, thereby activating factor X; factor VIII is present in cryoprecipitated plasma, and is also used to treat hemophilia A; recombinant factor VIII–rF VIII therapy is used for hemophilia A