antithrombin alfa

Action and Spectrum

Actions and Spectrum: 

antithrombin alfa is a recombinant form of human antithrombin III, which is a naturally occurring protein that acts as an anticoagulant. antithrombin alfa is used therapeutically to prevent and treat blood clots in patients with hereditary antithrombin deficiency or in those undergoing certain types of surgeries. 

The action of antithrombin alfa involves binding to and inhibiting several clotting factors, including thrombin and factor Xa, thereby preventing the formation of blood clots. This inhibition is achieved by enhancing the activity of antithrombin III, which is normally present in the blood but may be insufficient in patients with antithrombin deficiency. 

The spectrum of antithrombin alfa includes a broad range of clinical indications for the prevention and treatment of venous thromboembolism, including deep vein thrombosis, pulmonary embolism, and stroke. It can also be used as a prophylactic agent in patients undergoing high-risk surgeries, such as cardiac and orthopedic procedures. 

Overall, antithrombin alfa is a valuable therapeutic option for patients with antithrombin deficiency or those at risk of developing blood clots, and its use is supported by extensive clinical evidence. However, as with all medications, it may have side effects and should only be used under the guidance of a qualified healthcare provider. 

Drug Interaction

Adverse Reaction

Frequency defined 

1-10% 

Post procedural hemorrhage (5%) 

Hemorrhage (5%) 

Application site pruritus (5%) 

Hematuria (2%) 

Dizziness (2%) 

Hepatic enzyme changes (2%) 

Chest pain; non-cardiac (2%) 

Hematoma (2%) 

<1% 

Lightheadedness 

Bowel fullness 

Chills 

Hives 

Chest tightness 

Cramps 

Nausea 

Film over eyes 

Foul taste 

Black Box Warning

Black Box Warning: 

antithrombin alfa has a black box warning related to the potential risk of serious bleeding events. This warning emphasizes that the use of antithrombin alfa should be carefully considered in patients at increased risk of bleeding, such as those with a history of bleeding disorders or those taking medications which can increase the risk of bleeding, such as antiplatelet agents or anticoagulants. 

Contraindication / Caution

Contraindication/Caution: 

Contraindication 

antithrombin alfa is contraindicated in patients with known hypersensitivity to the medication or any of its components. It should not be used in patients who have a history of heparin-induced thrombocytopenia or other heparin-induced immune reactions. 

antithrombin alfa should also be used with caution in patients with active bleeding, recent major surgery or trauma, severe hypertension, or a history of stroke or intracranial hemorrhage. It is generally not recommended for use during pregnancy, as its safety in pregnant women has not been established. 

As with all medications, healthcare providers should carefully evaluate each patient’s medical history and current clinical condition before initiating treatment with antithrombin alfa. Patients with a high risk of bleeding or thrombosis may not be suitable candidates for this medication, and alternative treatments should be considered. 

If antithrombin alfa is being used in combination with other anticoagulant medications, such as heparin or warfarin, careful monitoring of coagulation parameters, such as international normalized ratio(INR),the activated partial thromboplastin time is necessary to avoid excessive anticoagulation and the risk of bleeding. 

Caution 

antithrombin alfa should be used with caution in patients with a history of bleeding disorders or those taking medications that increase the risk of bleeding, such as antiplatelet agents or anticoagulants. It is important to monitor these patients closely for signs of bleeding and adjust the dose of antithrombin alfa if necessary. 

The safety and efficacy of antithrombin alfa in pediatric patients have not been established, and it should be used with caution in elderly patients, as they may be more susceptible to adverse effects such as bleeding or thrombosis. 

antithrombin alfa should also be used with caution in patients with liver or kidney disease, as these conditions may affect the clearance of the medication from the body. Dose adjustments may be necessary in these patients. 

If antithrombin alfa is being used during surgery or other invasive procedures, the healthcare provider should be aware of the potential for bleeding and take appropriate precautions to minimize this risk. 

Overall, while antithrombin alfa is generally well-tolerated, caution should be exercised when using it in certain patient populations, and appropriate monitoring and dose adjustments should be made to minimize the risk of adverse effects. 

Pregnancy / Lactation

Pregnancy consideration:  

US FDA pregnancy category: C 

Lactation:   

Excreted into human milk is Not known.  

Pregnancy category: 

• Category A: well-controlled and Satisfactory studies do not show risk to the fetus in the first/later trimester.        
• Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women        
• Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.       
• Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.        
• Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.        
• Category N: There is no data available for the drug under this category 

Pharmacology

Pharmacology: 

antithrombin alfa is a recombinant form of human antithrombin III, a naturally occurring protein that plays a key role in regulating blood coagulation. Antithrombin III acts as an inhibitor of several coagulation factors, including thrombin and factor Xa, which are involved in the final stages of the coagulation cascade. 

antithrombin alfa works by binding to and neutralizing these coagulation factors, thereby inhibiting blood clot formation. This results in a decrease in thrombin generation and a reduction in the risk of thrombosis. 

Pharmacodynamics: 

Mechanism of action: It is serine protease inhibitor, a crucial natural agent that prevents blood coagulation by deactivating multiple active serine proteases involved in the coagulation cascade, such as thrombin, plasmin, and factors IXa, Xa, XIa, and XIIa. 

Pharmacokinetics: 

Absorption 

antithrombin alfa is administered intravenously, and as a result, it is rapidly and completely absorbed into the bloodstream. 

Distribution 

antithrombin alfa is distributed throughout the body, but its primary site of action is in the bloodstream. The volume of distribution of antithrombin alfa is approximately equal to the plasma volume. 

Metabolism 

antithrombin alfa is metabolized by both hepatic and renal mechanisms, but the exact metabolic pathways are not well characterized. It is believed that the medication is broken down into smaller peptides and amino acids. 

Elimination and Excretion 

antithrombin alfa is primarily eliminated from the body by renal excretion, with a small portion also eliminated through hepatic metabolism. The elimination half-life of antithrombin alfa is approximately 2-4 hours. 

Adminstartion

Administration: 

Intravenous administration 

antithrombin alfa is typically administered intravenously (IV) under the supervision of a healthcare provider. The dose and duration of treatment may vary depending on the indication and the patient’s clinical status. 

For the treatment of hereditary antithrombin deficiency, the recommended dose of antithrombin alfa is typically based on the patient’s weight and the degree of antithrombin deficiency. The medication is typically administered as a continuous infusion over several hours or days. 

For the prevention of blood clots during high-risk surgeries, such as cardiac or orthopedic procedures, antithrombin alfa is typically administered as a bolus injection immediately before or after surgery, followed by a continuous infusion over several days. 

During treatment with antithrombin alfa, the patient’s coagulation parameters, as activated partial thromboplastin time (aPTT) or anti-Xa levels, may be monitored to ensure adequate anticoagulation and minimize the risk of bleeding or thrombosis. 

antithrombin alfa should be stored at refrigerated temperatures and protected from light. Before administration, the medication should be inspected visually for particulate matter or discoloration. Any vials that appear to be damaged or contaminated should not be used. 

Overall, the administration of antithrombin alfa should be carried out by a healthcare professional with experience in the management of anticoagulant therapy, and the patient should be closely monitored for potential adverse effects. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: antithrombin alfa 

Why do we use antithrombin alfa? 

antithrombin alfa is a medication used to prevent and treat blood clots in certain patient populations. The medication is a recombinant form of human antithrombin III, a natural protein that plays a key role in regulating blood coagulation. 

Some of the specific uses of antithrombin alfa include: 

• Treatment of hereditary antithrombin deficiency, a rare genetic disorder that predisposes patients to recurrent blood clots. 
• Prevention of blood clots during high-risk surgeries, such as cardiac or orthopedic procedures. 
• Treatment of heparin resistance, a condition in which patients fail to respond adequately to heparin therapy. 
• Treatment of heparin-induced thrombocytopenia (HIT), a potentially life-threatening condition characterized by a low platelet count and increased risk of blood clots. 
• Management of disseminated intravascular coagulation (DIC), a disorder in which the body’s clotting system is activated inappropriately, leading to widespread clot formation and consumption of clotting factors.