Antithrombin III


Concise Prescribing Info
Indications/Uses
Listed in Dosage.
Dosage/Direction for Use
Adult : IV Thromboembolic disorders; Prophylaxis of thromboembolism associated w/ surgical and obstetric procedures Dosing is individualized based on clinical condition. Loading: Dose targeted to achieve 120% of normal AT level. Maintenance: Dose targeted to achieve 80-120% of normal AT level 24 hrly as needed.
Dosage Details
Intravenous
Prophylaxis of thromboembolism associated with surgical and obstetric procedures, Thromboembolic disorders
Adult: Dosing is individualised based on pre-therapy antithrombin (AT) level and clinical condition. Loading: Dose targeted to achieve 120% of normal AT level via infusion. Maintenance: Dose targeted to achieve 80-120% (approx 60% of initial loading dose) of normal AT level via infusion 24 hrly as needed.
Reconstitution
Allow the vials to reach room temp prior to reconstitution. Add 10 or 20 mL of sterile water for inj (w/o preservatives) to the vial containing approx 500 or 1,000 IU, respectively. Gently swirl to avoid foam formation. Filter through sterile filter needle provided by the manufacturer prior to admin.
Special Precautions
May carry a risk of transmitting infectious agents (e.g. viruses, Creutzfeldt Jakob disease agents). Pregnancy and lactation.
Adverse Reactions
Flushing, headache, dizziness, chest tightness, nausea, dysgeusia, chills, abdominal cramps, shortness of breath, lightheadedness, hives, fever; inj site oozing and haematoma. Rarely, allergic reactions.
IV/Parenteral: C (FDA Pregnancy Category B or C depending on the manufacturer.)
MonitoringParameters
Monitor vital signs, cardiac and CNS status during and after therapy. Monitor AT level at baseline, 20 min (peak) and 12 hr post-infusion, and before the next infusion (trough). Measure peak and trough AT levels w/ each subsequent dose until desired levels achieved.
Drug Interactions
May enhance anticoagulant effect and increase the risk of bleeding w/ heparin and other anticoagulants.
Action
Description: Antithrombin III, an α2-globulin, is the major inhibitor of in vivo coagulation. It inactivates thrombin, plasmin, and activated coagulation factors IXa, Xa, XIa, and XIIa, preventing the conversion of fibrinogen to fibrin, thereby inhibiting thrombus formation. Additionally, it is the cofactor through which heparin exerts in effect.
Pharmacokinetics:
Distribution: Distributed into plasma (39%), extravascular space (49%), and vascular endothelial cells (11%).
Metabolism: Metabolised (<5%) to low molecular wt breakdown products.
Excretion: Via urine (as complex w/ thrombin or other proteinases). Terminal elimination half-life: Biphasic; 2.5-4.8 days.
Storage
Store below 25°C. Do not freeze.
ATC Classification
B01AB02 - antithrombin III ; Belongs to the class of heparin group. Used in the treatment of thrombosis.
References
Anon. Antithrombin. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 22/09/2016.

Buckingham R (ed). Antithrombin III. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 22/09/2016.

McEvoy GK, Snow EK, Miller J et al (eds). Antithrombin III (Human). AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 22/09/2016.

Thrombate III – Human (Grifols USA, LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 22/09/2016.

Disclaimer: This information is independently developed by MIMS based on Antithrombin III from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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