Adult Dosing
Thromboembolic events in hereditary antithrombin deficient patients
Pregnant patients, peri-partum
- Loading dose: (100 - baseline AT activity level)/1.3 x Body Weight (kg)
- Maintenance dose: (100 - baseline AT activity level)/5.4 x Body Weight (kg)
Thromboembolic events in hereditary antithrombin deficient patients
Surgical Patients, peri-operative
- Loading dose: (100 - baseline AT activity level)/2.3 x Body Weight (kg)
- Maintenance dose: (100 - baseline AT activity level)/10.2 x Body Weight (kg)
Dose adjustments according to AT activity
Monitoring time, 2 hrs after treatment start
- If AT level <80%: Increase dose by 30%; recheck AT levels 2 hrs after each dose adjustment
- If AT level 80%-120%: No dose adjustment; recheck AT levels 6 hrs after treatment start or dose adjustment
- If AT level >120%: Decrease dose by 30%; recheck AT levels 2 hrs after each dose adjustment
Notes- Individualize dose based on pre-treatment AT activity level; start therapy prior to delivery or 24 hrs prior to surgery
- Maintain AT activity levels between 80%-120% of normal (0.8-1.2 IU/mL)
- Administer loading dose as a 15-min IV infusion immediately followed by continuous infusion of the maintenance dose
- Continue treatment until anticoagulation is established
- Monitor AT levels once or twice/day
Pediatric Dosing
- Safety and effectiveness in pediatric patients have not been established
See Supplemental Patient Information
- Hypersensitivity reactions including hives, generalized urticaria, tightness of the chest, wheezing, hypotension, and anaphylaxis may occur during infusion period. Discontinue therapy if anaphylaxis and severe hypersensitivity reactions occur and administer emergency treatment
- Addition or withdrawal of the antithrombin [recombinant] may alter the anticoagulation activity of other drugs containing antithrombin
- Perform aPTT and anti-Factor Xa activity, at close intervals, especially in the first hours following the start or withdrawal of the therapy. Monitor patients for bleeding or thrombosis
- Appropriately make dose adjustments by monitoring AT activity once or twice/day
Supplemental Patient Information
- Inform patients about the risk of bleeding when antithrombin(recombinant) is administered with other anticoagulants and instruct them to notify their physicians of any bleeding events while on treatment
Pregnancy Category:C
Breastfeeding: Antithrombin is excreted in breastmilk at levels of 1/50 to 1/100 of its concentration in the blood, which is same as estimated to be present in breast milk of normal lactating women, which is not harmful to breastfed neonates. However use cautiously in nursing woman if benefit outweigh the risks.
