Dosage Forms
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Injection, powder for reconstitution [human, preservative free]:
Thrombate III: 500 units, 1000 units [contains heparin; exact potency labeled on each vial]
Pharmacology
Mechanism of Action
Antithrombin is the primary physiologic inhibitor of in vivo coagulation. It is an alpha2-globulin. Its principal actions are the inactivation of thrombin, plasmin, and other active serine proteases of coagulation, including factors IXa, Xa, XIa, and XIIa. The inactivation of proteases is a major step in the normal clotting process. The strong activation of clotting enzymes at the site of every bleeding injury facilitates fibrin formation and maintains normal hemostasis. Thrombosis in the circulation would be caused by active serine proteases if they were not inhibited by antithrombin after the localized clotting process (Schwartz, 1989).
In patients with hereditary antithrombin (AT) deficiency, spontaneous thrombosis may occur due to decreased AT concentrations; therapy with human or recombinant AT restores functional AT activity.
Pharmacokinetics/Pharmacodynamics
Half-Life Elimination
Plasma derived (Thrombate III): Biologic: 2.5 days (immunologic assay); 3.8 days (functional AT assay). Half-life may be decreased following surgery, with hemorrhage, acute thrombosis, and/or during heparin administration.
Use: Labeled Indications
Hereditary antithrombin deficiency: Thrombate III: Treatment and prevention of thromboembolism and prevention of perioperative and peripartum thromboembolism in patients with hereditary antithrombin deficiency.
Use: Off Label
Intraoperative heparin resistance during cardiopulmonary bypassc
Data from a limited number of patients suggest that antithrombin may be beneficial to improve heparinization during cardiopulmonary bypass in patients with difficulty achieving therapeutic activated clotting time values Lemmer 2002.
Contraindications
Thrombate III: There are no contraindications listed in manufacturer's labeling.
Canadian labeling: Additional contraindications (not in US labeling): Hypersensitivity to antithrombin, other anticoagulants, or any component of the formulation.
Dosage and Administration
Dosing: Adult
Hereditary antithrombin deficiency:
Thrombate III: Prophylaxis of thrombosis during surgical or obstetrical procedures or treatment of thromboembolism:
IV:
Initial loading dose: Dosing is individualized based on pretherapy antithrombin (AT) levels. The initial dose should raise AT levels to 120% and may be calculated based on the following formula:
[(desired AT level % - baseline AT level %) x body weight (kg)] divided by 1.4 = units of antithrombin required
For example, if a 70 kg adult patient had a baseline AT level of 57%, the initial dose would be:
[(120% - 57%) x 70] divided by 1.4 = 3150 units
Maintenance dose: In general, subsequent dosing should be targeted to keep levels between 80% to 120%, which may be achieved by administering 60% of the initial loading dose every 24 hours. Adjustments may be made by adjusting dose or interval. Maintain level within normal range for 2 to 8 days depending on type of procedure/situation.
Intraoperative heparin resistance during cardiopulmonary bypass (off-label use):
Thrombate III: IV: Initial: 500 units once (dose can be rounded to the nearest vial size); a repeat dose of 500 units may be considered if activated clotting time remains subtherapeutic after the initial dose (Lemmer 2002).
Dosing: Geriatric
Refer to adult dosing.
Reconstitution
Thrombate III: Bring drug and diluent to room temperature prior to reconstitution. Reconstitute with sterile water for injection. Do not shake; swirl to mix to avoid foaming. Filter through sterile filter needle provided prior to administration.
Administration
IV: Thrombate III: Infuse over 10 to 20 minutes.
Dietary Considerations
Some products may contain sodium.
Storage
Thrombate III: Store intact vials at temperatures not exceeding 25°C (77°F); avoid freezing. Administer within 3 hours after reconstitution. Do not refrigerate reconstituted product.
Drug Interactions
Acalabrutinib: May enhance the anticoagulant effect of Anticoagulants. Monitor therapy
Agents with Antiplatelet Properties (e.g., P2Y12 inhibitors, NSAIDs, SSRIs, etc.): May enhance the anticoagulant effect of Anticoagulants. Monitor therapy
Apixaban: May enhance the anticoagulant effect of Anticoagulants. Refer to separate drug interaction content and to full drug monograph content regarding use of apixaban with vitamin K antagonists (eg, warfarin, acenocoumarol) during anticoagulant transition and bridging periods. Avoid combination
Bromperidol: May enhance the adverse/toxic effect of Anticoagulants. Monitor therapy
Caplacizumab: May enhance the anticoagulant effect of Anticoagulants. Monitor therapy
Collagenase (Systemic): Anticoagulants may enhance the adverse/toxic effect of Collagenase (Systemic). Specifically, the risk of injection site bruising and/or bleeding may be increased. Monitor therapy
Dabigatran Etexilate: May enhance the anticoagulant effect of Anticoagulants. Refer to separate drug interaction content and to full drug monograph content regarding use of dabigatran etexilate with vitamin K antagonists (eg, warfarin, acenocoumarol) during anticoagulant transition and bridging periods. Avoid combination
Dasatinib: May enhance the anticoagulant effect of Anticoagulants. Monitor therapy
Deferasirox: Anticoagulants may enhance the adverse/toxic effect of Deferasirox. Specifically, the risk for GI ulceration/irritation or GI bleeding may be increased. Monitor therapy
Deoxycholic Acid: Anticoagulants may enhance the adverse/toxic effect of Deoxycholic Acid. Specifically, the risk for bleeding or bruising in the treatment area may be increased. Monitor therapy
Desirudin: Anticoagulants may enhance the anticoagulant effect of Desirudin. Consider therapy modification
Edoxaban: May enhance the anticoagulant effect of Anticoagulants. Refer to separate drug interaction content and to full drug monograph content regarding use of edoxaban with vitamin K antagonists (eg, warfarin, acenocoumarol) during anticoagulant transition and bridging periods. Management: Some limited combined use may be indicated during periods of transition from one anticoagulant to another. See the full edoxaban drug monograph for specific recommendations on switching anticoagulant treatment. Avoid combination
Estrogen Derivatives: May diminish the anticoagulant effect of Anticoagulants. More specifically, the potential prothrombotic effects of some estrogens and progestin-estrogen combinations may counteract anticoagulant effects. Management: Carefully weigh the prospective benefits of estrogens against the potential increased risk of procoagulant effects and thromboembolism. Use is considered contraindicated under some circumstances. Refer to related guidelines for specific recommendations. Exceptions: Tibolone. Consider therapy modification
Fat Emulsion (Fish Oil Based): May enhance the anticoagulant effect of Anticoagulants. Monitor therapy
Hemin: May enhance the anticoagulant effect of Anticoagulants. Avoid combination
Heparin: Antithrombin may enhance the anticoagulant effect of Heparin. Monitor therapy
Heparins (Low Molecular Weight): Antithrombin may enhance the anticoagulant effect of Heparins (Low Molecular Weight). Monitor therapy
Herbs (Anticoagulant/Antiplatelet Properties) (eg, Alfalfa, Anise, Bilberry): May enhance the adverse/toxic effect of Anticoagulants. Bleeding may occur. Management: Avoid such combinations when possible. If used concomitantly, increase diligence in monitoring for adverse effects (eg, bleeding, bruising, altered mental status due to CNS bleeds). Consider therapy modification
Ibritumomab Tiuxetan: Anticoagulants may enhance the adverse/toxic effect of Ibritumomab Tiuxetan. Both agents may contribute to an increased risk of bleeding. Monitor therapy
Ibrutinib: May enhance the adverse/toxic effect of Anticoagulants. Monitor therapy
Inotersen: May enhance the anticoagulant effect of Anticoagulants. Monitor therapy
Limaprost: May enhance the adverse/toxic effect of Anticoagulants. The risk for bleeding may be increased. Monitor therapy
MiFEPRIStone: May enhance the adverse/toxic effect of Anticoagulants. Specifically, the risk of bleeding may be increased. Avoid combination
Nintedanib: Anticoagulants may enhance the adverse/toxic effect of Nintedanib. Specifically, the risk for bleeding may be increased. Monitor therapy
Nonsteroidal Anti-Inflammatory Agents (COX-2 Selective): May enhance the anticoagulant effect of Anticoagulants. Monitor therapy
Obinutuzumab: Anticoagulants may enhance the adverse/toxic effect of Obinutuzumab. Specifically, the risk of serious bleeding-related events may be increased. Monitor therapy
Omacetaxine: Anticoagulants may enhance the adverse/toxic effect of Omacetaxine. Specifically, the risk for bleeding-related events may be increased. Management: Avoid concurrent use of anticoagulants with omacetaxine in patients with a platelet count of less than 50,000/uL. Avoid combination
Omega-3 Fatty Acids: May enhance the anticoagulant effect of Anticoagulants. Monitor therapy
Pentosan Polysulfate Sodium: May enhance the anticoagulant effect of Anticoagulants. Monitor therapy
Progestins: May diminish the therapeutic effect of Anticoagulants. More specifically, the potential prothrombotic effects of some progestins and progestin-estrogen combinations may counteract anticoagulant effects. Management: Carefully weigh the prospective benefits of progestins against the potential increased risk of procoagulant effects and thromboembolism. Use is considered contraindicated under some circumstances. Refer to related guidelines for specific recommendations. Consider therapy modification
Prostacyclin Analogues: May enhance the adverse/toxic effect of Anticoagulants. Specifically, the antiplatelet effects of these agents may lead to an increased risk of bleeding with the combination. Monitor therapy
Rivaroxaban: Anticoagulants may enhance the anticoagulant effect of Rivaroxaban. Refer to separate drug interaction content and to full drug monograph content regarding use of rivaroxaban with vitamin K antagonists (eg, warfarin, acenocoumarol) during anticoagulant transition and bridging periods. Avoid combination
Salicylates: May enhance the anticoagulant effect of Anticoagulants. Monitor therapy
Sugammadex: May enhance the anticoagulant effect of Anticoagulants. Monitor therapy
Sulodexide: May enhance the anticoagulant effect of Anticoagulants. Monitor therapy
Thrombolytic Agents: May enhance the anticoagulant effect of Anticoagulants. Management: See full drug monograph for guidelines for the use of alteplase for acute ischemic stroke during treatment with oral anticoagulants. Monitor therapy
Tibolone: May enhance the anticoagulant effect of Anticoagulants. Monitor therapy
Tipranavir: May enhance the anticoagulant effect of Anticoagulants. Monitor therapy
Urokinase: May enhance the anticoagulant effect of Anticoagulants. Avoid combination
Vitamin E (Systemic): May enhance the anticoagulant effect of Anticoagulants. Monitor therapy
Vitamin K Antagonists (eg, warfarin): Anticoagulants may enhance the anticoagulant effect of Vitamin K Antagonists. Monitor therapy
Vorapaxar: May enhance the adverse/toxic effect of Anticoagulants. More specifically, this combination is expected to increase the risk of bleeding. Avoid combination
Zanubrutinib: May enhance the adverse/toxic effect of Anticoagulants. Monitor therapy
Adverse Reactions
1% to 10%:
Cardiovascular: Chest pain (≤2%)
Central nervous system: Dizziness (2%)
Gastrointestinal: Liver enzyme abnormalities (≤2%)
Genitourinary: Hematuria (≤2%)
Hematologic & oncologic: Hemorrhage (≥5%), hematoma (≤2%)
Local: Infusion site reaction (≥5%)
Neuromuscular & skeletal: Hemarthrosis (≤2%)
<1%, postmarketing, and/or case reports: Blurred vision, chest tightness, chills, dizziness, dyspnea, fever, gastrointestinal fullness, muscle cramps, nausea, unpleasant taste, urticaria
Warnings/Precautions
Concerns related to adverse effects:
- Hypersensitivity reactions: Hypersensitivity reactions, including severe hypersensitivity reactions (eg, anaphylaxis), may occur; monitor closely during infusions. If hypersensitivity symptoms occur, discontinue immediately and institute supportive emergency care.
- Infections: Thrombate III: Thrombate III is AT collected from pooled human plasma (hpAT). A product of human plasma, it may potentially contain infectious agents which could transmit disease, including the Creutzfeldt-Jakob Disease (CJD) agent; screening of donors, as well as testing and/or inactivation or removal of certain viruses, reduces this risk. Infections suspected to be transmitted by this product should be reported to the manufacturer.
Concurrent drug therapy issues:
- Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.
Other warnings/precautions:
- Pharmacokinetic differences: Half-life and clearance differ significantly (~7 to 9 times) between the plasma-derived and the recombinant-derived product.
Monitoring Parameters
Hereditary antithrombin deficiency:
Thrombate III: Initially, monitor antithrombin (AT) at baseline, 20 minutes postinfusion (peak), 12 hours postinfusion, then preceding next infusion (trough level). Measure peak and trough AT levels with each subsequent dose until predictable levels achieved (between 80% and 120%). Some situations (eg, following surgery, hemorrhage or acute thrombosis, concurrent IV heparin administration), may require more frequent AT monitoring.
AT concentrations in neonates of parents with hereditary AT deficiency should be measured immediately after birth.
Intraoperative heparin resistance during cardiopulmonary bypass (off-label use):
Due to laboratory turn-around times, routine monitoring of AT levels before or after Thrombate III administration is not feasible in the intraoperative setting. Therefore, therapeutic response should be monitored with activated clotting time (Lemmer 2002).
Pregnancy
Pregnancy Considerations
The risk of thromboembolic events such as venous thromboembolism (VTE) is increased in patients with hereditary antithrombin (AT) deficiency. Pregnancy-induced physiologic changes also increase this risk; risk is dependent upon maternal antithrombin levels and personal or family history of thromboembolism (ACOG 197 2018). Thrombate III is approved for use in pregnant women with hereditary AT deficiency to replace endogenous antithrombin and reduce the risk of peripartum thromboembolism. Antithrombin replacement can be used in pregnant patients with hereditary AT deficiency in high-risk settings (eg, childbirth, miscarriage, surgery) when other anticoagulant therapy (eg, low molecular weight heparin [LMWH]) is withheld or as adjunctive therapy to LMWH in pregnant women at high risk for VTE (Bauer 2016; Ilonczai 2015; James 2017; Rogenhofer 2014).
Patient Education
What is this drug used for?
- It is used to treat antithrombin deficiency.
Frequently reported side effects of this drug
- Cramps
- Change in taste
Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:
- Chest pain
- Severe dizziness
- Passing out
- Severe nausea
- Vomiting
- Burning or numbness feeling
- Restlessness
- Shortness of breath
- Signs of a significant reaction like 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. Talk to your doctor if you have questions.
Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.
