Thrombate III Mixes in Minutes and Restores Antithrombin Levels.

Each bottle of Thrombate III has the functional activity, in international units (IU), stated on the label of the bottle. The potency assignment has been determined using a standard calibrated against a World Health Organization AT reference preparation.¹

Dosage should be determined on an individual basis based on the pre-therapy plasma AT level, in order to increase plasma AT levels to the level found in normal human plasma (100%).

Dosage of Thrombate III can be calculated from the following formula¹:

^a Expressed as a percent of normal based on functional AT assay.
^b Body weight of the patient.

Thus, if a 70-kg individual has a baseline plasma AT level of 57%, in order to increase plasma AT to the desired level of 120%, the initial loading dose of Thrombate III would be ([120–57] x 70)/1.4 = 3150 IU total.

As a general recommendation, the following therapeutic program may be used as a starting program for treatment, modifying the program based on the actual plasma AT-III levels achieved¹:

An initial loading dose of Antithrombin III (Human) Thrombate III calculated to elevate the plasma AT-III level to 120%, assuming an expected rise over the baseline plasma AT-III level of 1.4% (functional activity) per IU per kg of Thrombate III administered. Thus, if an individual has a baseline AT-III level of 57%, the initial Thrombate III dose would be (120–57)/1.4 = 45 IU/kg
Measure preinfusion and 20 minutes postinfusion (peak) plasma antithrombin III levels following the initial loading dose, plasma antithrombin III level after 12 hours, then preceding the next infusion (trough level). Subsequently measure antithrombin III levels preceding and 20 minutes after each infusion until predictable peak and trough levels have been achieved, generally between 80% and 120%
Plasma levels between 80% and 120% may be maintained by administration of maintenance doses of 60% of the initial loading dose, administered every 24 hours. Adjustments in the maintenance dose and/or interval between doses should be made based on actual plasma AT-III levels achieved

Reference:

Thrombate III [prescribing information]. Research Triangle Park, NC: Talecris Biotherapeutics, Inc.; 2009.

Important Safety Information

Thrombate III is indicated for the treatment of patients with hereditary antithrombin deficiency in connection with surgical or obstetrical procedures or when they suffer from thromboembolism.

In clinical studies with Thrombate III, the most common side effects were dizziness, chest tightness, nausea, and foul taste in the mouth.

The anticoagulant effect of heparin is enhanced by concurrent treatment with Thrombate III in patients with hereditary AT-III deficiency. Thus, in order to avoid bleeding, reduced dosage of heparin is recommended during treatment with Thrombate III.

Thrombate III is made from human plasma. Products made from human plasma may contain infectious agents, such as viruses, and, theoretically, the Creutzfeldt-Jakob disease (CJD) agent that can cause disease. There is also the possibility that unknown infectious agents may be present in such products.

Individuals who receive infusions of blood or blood plasma may develop signs and/or symptoms of some viral infections, particularly hepatitis C.

Please speak to your doctor and refer to Thrombate III Prescribing Information for full details.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.