Dosing and uses of Thrombate III (antithrombin III)
Adult dosage forms and strengths
powder for injection
- 500 International Units
- 1000 International Units
Determine Dosage on an Individual Basis
Base on pre-therapy plasma antithrombin III (AT-III) leveL
In order to increase plasma AT-III levels to that found in normal human plasma
Heparin Resistance (Orphan)
Treatment of antithrombin III dependent heparin resistance requiring anticoagulation
Orphan indication sponsor
- AT III LLC; c/o Genzyme Corporation,15 Pleasant St. Connector, P.O. Box 9322; Framingham, MA 01701
Other Information
Calculate dosage from following formula: (*expressed as percentage normal level based on functional AT-III assay) Unit required (International Units) = {[desired-baseline AT-III level*] x weight (kg)}/1.4
Subsequent doses can be calculated based on recovery of first dose
Monitor: following initial dose, plasma AT-III at least q12hr & before next infusion
Other Indications & Uses
Hereditary antithrombin III deficiency in conjunction with surgical or obstetrical procedures or thromboembolism
Pediatric dosage forms and strengths
Safety & efficacy not established
Thrombate III (antithrombin III) adverse (side) effects
1-10%
Dizziness (7%)
<1%
Bowel fullness
Chest pain/tightness
Chills
Cramps
Dysgeusia
Dyspnea
Hives
Fever
Film over eye
Lightheadedness
Nausea
Oozing & hematoma
Warnings
Cautions
Administer within 3 hr after reconstitution; do not refrigerate after reconstitution
Made from human plasma : theoretical risk of blood-borne pathogens
Pregnancy and lactation
Pregnancy category: B
Lactation: not known if distributed into breast milk, use caution
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Thrombate III (antithrombin III)
Half-Life: 2.5-4.8 d
Mean 50% disappearance time: 22 hr
Mechanism of action
Purified human antithrombin III
Administration
IV Preparation
Reconstitute aseptically w/ SWI (supplied: 10 mL for 500 IU & 20 mL for 1000 IU)
Bring to room temperature prior to administration
Contents of multiple vials may be drawn into same syringe through filter needles provided, if pt. needs more than one viaL
IV Administration
Administer within 3 hr after reconstitution
Rate of administration should be adapted to response of pt.; generally infusion over 10-20 min well tolerated
Storage
Room temp upto 25°C (77°F)
