Atryn (antithrombin III, human recombinant)
Plasma Proteins Which Facilitate Anticoagulation Intravenous Vial (Ea)
Last reviewed · Source: First Databank (FDB) drug data
Overview
Antithrombin alfa (antithrombin (recombinant)) is a biosynthetic (recombinant DNA origin) preparation of human antithrombin III, a naturally occurring anticoagulant.
Antithrombin alfa is a biosynthetic (recombinant DNA origin) preparation of human antithrombin III produced in the milk of transgenic goats. The transgenic technology involves insertion of the DNA coding sequence for human antithrombin III into the specific promotor gene that directs expression of the protein in the goat mammary gland. Antithrombin alfa is isolated and purified from goat milk using a series of filtration and chromatography steps.
Goats used in the production of antithrombin alfa are inspected, controlled for specific pathogens, and certified scrapie-free by the US Department of Agriculture (USDA). Additional purification processes are employed to remove and/or inactivate potential viruses or pathogens present in the goat herd. Antithrombin alfa does not contain any preservatives nor is it formulated with human plasma proteins.
Antithrombin III plays a central role in hemostasis by regulating several key serine proteases in the blood coagulation pathway. Antithrombin III principally inhibits the activity of thrombin and factor Xa, and to a lesser extent, factors IXa, XIa, XIIa, trypsin, plasmin, tissue plasminogen activator (tPA), urokinase (no longer commercially available in the US), and kallikrein. Irreversible complexes are formed between antithrombin III and its target protease, neutralizing the activity of the serine protease; the resulting complexes are then rapidly removed from the circulation by the liver.
Such a reaction is enhanced by more than 300- to 1000-fold in the presence of endogenous or exogenous heparin bound to antithrombin. Antithrombin III also exhibits anti-inflammatory and antiproliferative effects in the endothelium.
Antithrombin alfa is functionally and structurally similar to endogenous human antithrombin III but differs in its glycosylation structure; this difference is thought to result in increased (about fourfold) heparin affinity. Compared to plasma-derived antithrombin III, antithrombin alfa has a shorter half-life and more rapid clearance. The mean half-life of antithrombin alfa following a single IV dose of 50 or 100 units/kg in patients with congenital antithrombin III deficiency during non-high-risk situations is 11.6 or 17.7 hours, respectively.
Surgery, pregnancy, bleeding, or concomitant administration of heparin may affect the pharmacokinetics of antithrombin alfa. In pregnant women, clearance and volume of distribution of antithrombin alfa are increased compared with nonpregnant women or with men.
Generic name: antithrombin III, human recombinant
Drug class: Plasma Proteins Which Facilitate Anticoagulation
Therapeutic class: Hematological Agents
Reference product & biosimilars
No reference, biosimilar or interchangeable associated with this drug.
Today’s intelligence on Atryn
Indications
The following indications are listed for Atryn:
- Antithrombin Iii Deficiency
Also known as: Atiii Deficiency.
Dosing
Potency of antithrombin alfa is expressed in international units (IU, units) as tested against the activity of the World Health Organization reference standard. Each vial is labeled with the number of units of antithrombin alfa (approximately 1750 units per vial).
Dosage of antithrombin alfa is individualized based on the patient's weight, baseline antithrombin III activity, and serial monitoring of serum antithrombin III activity levels (expressed as a percentage of normal). The goal of therapy is to achieve an antithrombin III activity level of 80-120% of normal. Serum antithrombin III levels should be monitored prior to and at regular intervals (i.e., once or twice daily) during therapy to ensure such target antithrombin III activity levels.
Dosage of antithrombin alfa differs in pregnant versus nonpregnant women because clearance and volume of distribution of the drug are increased in pregnant women. (See Description.)
No dosing information is available for this tab.
No dosing information is available for this tab.
No dosing information is available for this tab.
Drug interactions
There is no enhanced messaging for this drug.
There are no contraindication interactions for this drug.
There are no severe interactions for this drug.
There are no moderate interactions for this drug.
Contraindications
Known hypersensitivity to goat and goat milk proteins.
There are no contraindication contraindications for this drug.
There are no severe contraindications for this drug.
- Hemorrhage
- Thromboembolic disorder
Adverse reactions
The most common adverse effects reported in patients receiving antithrombin alfa in clinical studies were hemorrhage and infusion-site reactions.
More Frequent
- Hemorrhage
Rare or Very Rare
- Chest pain
More Frequent
- Injection site sequelae
Rare or Very Rare
- Abnormal hepatic function tests
Precautions
No enhanced messaging available.
Safety and efficacy not established in pediatric patients younger than 18 years of age.
Category C. (See Users Guide.)
Adequate and well-controlled studies of antithrombin alfa have not been conducted in pregnant women. In rats receiving antithrombin alfa in dosages of 210 mg/kg daily (5-6 times the usual human dose in pregnant women), a slight (but statistically significant) increase in pup mortality was seen when the drug was administered throughout most of pregnancy and the entire lactation period; however, no adverse effects were observed in another rat study when the same dose of antithrombin alfa was administered around parturition and during lactation. Antithrombin alfa does not appear to be associated with an increased risk of fetal abnormalities when administered to pregnant women during the third trimester. In premarketing clinical studies, 22 pregnant women with congenital antithrombin III deficiency received antithrombin alfa around parturition; no treatment-related adverse effects were reported in the 22 neonates born to these women. The drug should be used during pregnancy only if clearly indicated.
Antithrombin alfa is distributed into breast milk at concentrations estimated to be 1-2% of those found in maternal blood. Although such milk concentrations are similar to those found in normal lactating women and are not known to be harmful, the manufacturer states that caution should be exercised when antithrombin alfa is used during breast-feeding. The drug should be used in nursing women only if clearly indicated.
Clinical studies of antithrombin alfa did not include sufficient numbers of patients 65 years of age and older to determine whether geriatric patients respond differently than younger patients. In general, geriatric patients should receive initial dosages of antithrombin alfa at the lower end of the usual range because of the greater frequency of decreased hepatic, renal, and/or cardiac function and of concomitant disease and drug therapy in such individuals.
ICD codes
| Code | Type | Description |
|---|---|---|
| Antithrombin III deficiency | ||
| D68.59 | ICD10CM | Other primary thrombophilia |
ICD code information from First Databank (FDB).
Formulary status
Search health-plan coverage for this drug by ZIP code.
Choose the first character of a health plan name.
Last reviewed · Source: First Databank (FDB) drug data
On this page
Actions
Sign in to save favorites
Saving this drug requires a free Physicians Office Resource account.