Adult Dosing
Treatment of thromboembolism, hereditary antithrombin deficiency
Prevention of thromboembolism, hereditary antithrombin deficiency
Notes- Individualize loading dose and maintenance dose based on individual clinical conditions, response to therapy and actual plasma AT-III levels achieved
- Dosage is based on pretherapy antithrombin-III level
- Monitor baseline levels and levels at 20 mins post infusion to calculate subsequent doses based on recovery of first dose
- Monitor plasma levels of AT-III q12 hrs after initial dose and before the next infusion to maintain plasma antithrombin-III levels >80%
Initial dose
- Units required= [Desired - Baseline AT-III level] x weight(kg)/1.4
- Desired levels of AT-III IU/Kg: Desired - Baseline AT-III level /1.4
- Raise AT-III levels to normal and maintain for 2-8 days
Maintenance dose
- 60% of initial dose administered q 24 hrs
Pediatric Dosing
- Safety and effectiveness in pediatric patients have not been established
See Supplemental Patient Information
- For intravenous only
- AT-III plasma levels should be monitored during the treatment period
- AT-III levels should be monitored more frequently in certain situations like following surgery, hemorrhage/acute thrombosis, and during intravenous heparin administration due to reports of shortened half-life
- Determination of antithrombin III concentrations immediately after birth recommended in neonates of parents with congenital antithrombin III deficiency
- Risk of thrombosis associated with pregnancy and surgery in patients with congenital antithrombin III deficiency
- Investigations to determine possible thrombophilia should not be performed after a recent thromboembolic event/during anticoagulant therapy since antithrombin III concentrations are reduced
- Products made from human plasma may contain viruses, Creutzfeldt-Jakob agent that may cause disease
- Risk of the product transmitting infections can be reduced by screening plasma donors for presence of such viruses; still risk of transmission of disease exists
- Signs and symptoms of viral infections particularly hepatitis C may occur in individuals receiving infusions of blood or plasma products
- Discuss potential risk and benefits with the individual before prescribing or administering product to a patient
- Reduce dosage of heparin during concomitant use with Thrombate III
- Obtain emergency medical attention on occurrence of injury due to percutaneous puncture with a needle contaminated with blood
- Consider familial history of venous thrombosis, decreased plasma AT-III levels and exclusion of acquired deficiency for diagnosis of antithrombin III deficiency
- Reconstitute and use within 3 hrs, do not refrigerate after reconstitution
- Avoid mixing with diluting solutions or with other agents
- Administer the product with utmost care
- Follow biohazard procedures to discard equipments including reconstituted antithrombin III
- Periodically monitor AT-III levels during therapy
Caution: Use cautiously in:
- Concomitant use with heparin
Supplemental Patient Information
- Instruct women to inform if they are or plan to become pregnant or plan to breast-feed
Pregnancy Category:B
Breastfeeding: Safety unknown. Manufacturer recommends using only if benefits outweigh risks.
US Trade Name(s)
US Availability
Thrombate III
- PWDR for INJ: 500 IU/vial
Canadian Trade Name(s)
Canadian Availability
antithrombin III (generic)
- PWDR for INJ: 450-550 lU/vial
- PWDR for INJ: 900-1100 lU/vial
- PWDR for INJ: 1350-1650 IU/vial
Thrombate III
- PWDR for INJ: 500, 1000 IU/vial
UK Trade Name(s)
UK Availability
Australian Trade Name(s)
Australian Availability
Thrombotrol-VF
- PWDR for INJ: 1000 IU/vial