antithrombin III (redirected from Thrombate III)

antithrombin /an·ti·throm·bin/ (-throm´bin) any naturally occurring or therapeutically administered substance that neutralizes the action of thrombin and thus limits or restricts blood coagulation.

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antithrombin I  fibrin, referring to its capacity to adsorb thrombin and thus neutralize it.

antithrombin III  a plasma α of the serpin family that inactivates thrombin and also inhibits certain coagulation factors and kallikrein. Inherited deficiency is associated with recurrent deep vein thrombosis and pulmonary emboli; the complications are prevented and treated with a preparation of antithrombin III from pooled human plasma.

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antithrombin [an″te-throm´bin]

any naturally occurring or therapeutically administered substance that neutralizes the action of thrombin and thus limits or restricts blood coagulation.

antithrombin I fibrin, referring to the capacity of fibrin to adsorb thrombin and thus neutralize it.

antithrombin III a naturally occurring inhibitor of blood coagulation; it is an α₂-globulin member of the serpin group, synthesized in the liver and found in the plasma and various extravascular sites. It inactivates thrombin as well as certain coagulation factors and kallikrein. Inherited deficiency of the protein, an autosomal dominant disorder, is associated with recurrent deep vein thrombosis and pulmonary emboli. Complications from the disorder are prevented and, in conjunction with heparin, treated with a preparation of antithrombin III from pooled human plasma, administered intravenously.

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antithrombin III, human (AT-III, heparin cofactor 1)

Thrombate III

Pharmacologic class: Blood derivative, coagulation inhibitor

Therapeutic class: Antithrombin

Pregnancy risk category B

Action

Inactivates thrombin and activated forms of factors IXa, Xa, XIa, and XIIa, thereby inhibiting coagulation and thromboembolism formation

Availability

Injection: 500 international units, 1,000 international units

⊘Indications and dosages

➣ Thromboembolism related to AT-III deficiency

Adults: Initial dosage is individualized to amount required to increase AT-III activity to 120% of normal (determined 20 minutes after administration). Usual infusion rate is 50 to a maximum of 100 international units/minute I.V. Dosage calculation is based on anticipated 1.4% increase in plasma AT-III activity produced by 1 international unit/kg of body weight.

Use this formula to calculate dosage: Required dosage (international units) equals desired activity (%) minus baseline AT-III activity (%) multiplied by weight (kg) divided by 1.4 (international units/kg).

Maintenance dosage is individualized to amount required to maintain AT-III activity at 80% of normal.

Contraindications

None

Precautions

Use cautiously in:
• pregnant or breastfeeding patients
• children (safety and efficacy not established).

Administration

• Reconstitute drug concentrate with 10 ml of sterile water, normal saline solution, or dextrose 5% in water.
• Use filter needle provided by manufacturer to draw up solution.
• Don't shake vial.
• Know that drug may be diluted further in same solution if desired.
• Don't mix with other solutions.
• Infuse over 10 to 20 minutes.
• Administer within 3 hours of reconstitution.
☞ If adverse reactions occur, decrease infusion rate or, if indicated, stop infusion until symptoms disappear.

Route	Onset	Peak	Duration
I.V.	Immediate	Unknown	4 days

Adverse reactions

CNS: dizziness, light-headedness, headache

CV: vasodilation, reduced blood pressure, chest pain

EENT: perception of "film" over eyes

GI: nausea, sensation of intestinal fullness

GU: diuresis

Musculoskeletal: muscle cramps

Respiratory: dyspnea, shortness of breath

Skin: urticaria, oozing lesions, hives, hematoma

Other: foul taste, chills, fever

Interactions

Drug-drug. Heparin: increased anticoagulant effect

Patient monitoring

• Monitor AT-III activity levels regularly.
☞ Watch for signs and symptoms of too-rapid infusion, such as dyspnea and hypertension.
• Monitor vital signs and temperature.
• Assess fluid intake and output to detect dehydration.

Patient teaching

☞ Instruct patient to immediately report chest tightness, dizziness, and fever.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
• Advise patient to minimize GI upset and unpleasant taste by eating small, frequent servings of healthy food and drinking plenty of fluids.
• Tell patient that he'll undergo regular blood testing during therapy.
• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs mentioned above.

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antithrombin III

Hematology A 58 kD α₂-glycoprotein with a single polypeptide chain that inactivates serine proteases–thrombin and other coagulation proteins including factor Xa, IXa, kallikrein and others by an irreversible heparin-dependent reaction Function AT III dissolves blood clots that normally form within the circulation; heparin's anticoagulant activity hinges on activation of AT-III; AT-III-deficient individuals do not benefit from heparin therapy; ↓ AT-III may be a congenital AD condition, or acquired, occurring in DIC–due to 'consumption' or in liver disease–due to ↓ AT-III production, resulting in an ↑ risk of coagulation; AT III is ↓ in congenital deficiency, liver transplant, DIC, nephrotic syndrome, cirrhosis, chonic liver disease, carcinoma, mid-menstrual cycle; AT III is defective in 0.14% to 0.5% of the general population. See Hereditary thrombophilia, Recombinant human antithrombin III.