Antithrombin III

Antithrombin III is a prescription medication indicated in patients with hereditary antithrombin deficiency for:

• Treatment and prevention of thromboembolism
• Prevention of peri-operatieva and per-partum thromboembolism
• Antithrombin III is available under the following different brand names: Thrombate III

Common side effects of Antithrombin III include:

• Dizziness, and
• Pain, redness, or irritation at the injection site

Serious side effects of Antithrombin III include:

• Hives,
• Difficulty breathing,
• Swelling of the face, lips, tongue, or throat,
• Rash,
• Itching,
• Bloody, black, or tarry stools,
• Red or dark urine,
• Coughing up blood,
• Vomit that looks like coffee grounds,
• Red spots on the skin,
• Easy bruising,
• Unusual bleeding,
• Chest pain,
• Shortness of breath,
• Pain, swelling, or warmth in the leg,
• Severe headaches,
• Sudden numbness or weakness,
• Trouble walking,
• Dizziness, and
• Loss of coordination

Rare side effects of Antithrombin III include:

• none 

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors;
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
• Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult dosage

Powder for injection

• 500 Units
• 1000 Units

Therapeutic Goal

Adult dosage

• Increase & maintain antithrombin activity between 80-120 percent (0.8-1.2 International Unit/mL) during treatment
• Loading dose should target 100 percent AT activity level based on weight & pretreatment AT activity level

Surgical Patients

Adult dosage

• Initial dose should raise AT levels to 120 percentage
• Load = [(120 - baseline AT activity level in %) x kg Body Weight]/1.4 = units of antithrombin required intravenous

Maintenance

• Target subsequent dosing to keep levels between 80-120 percent, which may be achieved by administering 60% of the initial loading dose every 24 hours
• May adjust therapy by changing the dose or interval
• Maintain target level for 2-8 days depending on the type of procedure/situation

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

• Antithrombin III has severe interactions with the following drugs
  • mifepristone
• Antithrombin III has serious interactions with at least 54 other drugs.
• Antithrombin III has moderate interactions with at least 116 other drugs.
• Antithrombin III has minor interactions with the following drugs:
  • acetaminophen
  • acetaminophen IV
  • acetaminophen rectal
  • alprostadil intracavernous/urethral
  • ceftaroline
  • chlorella
  • demeclocycline
  • dexmethylphenidate
  • doxycycline
  • glyburide
  • mineral oil
  • minocycline
  • oxytetracycline
  • quinidine
  • serdexmethylphenidate/dexmethylphenidate
  • tetracycline
  • verteporfin
  • vitamin E

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all your products. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, or if you have health questions or concerns.

Contraindications

• None listed in the FDA-approved manufacturing labeling

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Antithrombin III?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Antithrombin III?”

Cautions

• Hypersensitivity, including anaphylactic reactions, may occur; monitor closely; discontinue immediately and administer appropriate care if symptoms occur
• Theoretical risk of blood-borne pathogens as it is a plasma product; risk is reduced by a screening of donors and testing and/or inactivation or removal of viruses; report to manufacturer infections suspected from product

Pregnancy and Lactation

• May be acceptable during pregnancy
• Lactation
  • Not known if distributed into breast milk, use caution