Atryn Side Effects Center

Last updated on RxList: 10/25/2021
Atryn Side Effects Center

What Is Atryn?

ATryn (recombinant lyophilized powder) is a recombinant human antithrombin used to prevent peri-operative and peri-partum thromboembolic events in hereditary antithrombin deficient patients. ATryn does not treat thromboembolic events in hereditary antithrombin deficient patients.

What Are Side Effects of Atryn?

Common side effects of ATryn include:

Dosage for Atryn

The dosage of ATryn is individualized based on the patient's pretreatment functional AT activity level and body weight and using therapeutic drug monitoring.

What Drugs, Substances, or Supplements Interact with Atryn?

ATryn may interact with anticoagulants, such as heparin. Tell your doctor all medications and supplements you use.

Atryn During Pregnancy or Breastfeeding

During pregnancy, ATryn should be used only if prescribed. This drug passes into breast milk. Consult your doctor before breastfeeding.

Additional Information

Our ATryn (recombinant lyophilized powder) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Atryn Professional Information


The serious adverse reaction that has been reported in clinical studies is hemorrhage (intra-abdominal, hemarthrosis and post procedural). The most common adverse events reported in clinical trials at a frequency of ≥ 5% are hemorrhage and infusion site reaction.

Clinical Trial Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Adverse reactions that occurred in clinical trials with hereditary AT deficient patients are shown in Table 3 by System Organ Class.

Table 3: Adverse Reactions in Hereditary AT Deficient Patients (one event per patient, 2% of total population, n=47)

Gastrointestinal Disorders

Intra-abdominal Hemorrhage

General Disorders and Administration Site Disorders

Application Site Pruritus
Feeling Hot
Non-cardiac Chest Pain


Hepatic Enzyme Abnormal

Musculoskeletal and Connective Tissue Disorders


Renal and Urinary Disorders


Vascular Disorders



For ATryn, a potential safety issue is the development of an immunological reaction to the recombinant protein or any of the potential contaminating proteins. Assays were developed and used to detect antibodies directed against antithrombin (Recombinant), goat AT, or goat-milk proteins. No confirmed specific immunological reaction was seen in any of the patients tested, nor were there any clinical adverse events that might indicate such a response.

A post-marketing patient registry has been established to collect additional data on the immunogenic potential of ATryn in patients treated with ATryn on more than one occasion. Physicians are encouraged to participate in the registry by collecting pre- and post-treatment serum samples from patients according to instructions provided by rEVO Biologics, Inc. and submitting them to rEVO Biologics, Inc. for analysis for the development of antibodies to antithrombin (Recombinant). Serum samples should be collected within one week before initiation of treatment and on days 1, 7 and 28 days from initiation of treatment. Physicians wanting to participate in this program are encouraged to contact rEVO Biologics, Inc. at 1-800-610-3776. rEVO Biologics, Inc. will provide detailed instructions for the collection, processing and shipping of samples, as well as all tubes and labels that are necessary for the collection and processing of samples.

Read the entire FDA prescribing information for Atryn (Recombinant Lyophilized Powder)


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© Atryn Patient Information is supplied by Cerner Multum, Inc. and Atryn Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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