How Blood Clots Are Treated

Show Article Table of Contents

There are three general categories of drugs that are commonly used to prevent or treat blood clots (thrombosis)—anticoagulants, fibrinolytics, and antiplatelet medications. Some of these (Pradaxa, Angiomax, ReoPro) may be unfamiliar, while others (warfarin, heparin, aspirin) are generally household names. They have different mechanisms of action, different risks, and are used under different circumstances. One potential side effect common to all of them is excessive bleeding, so all of these drugs must be used with appropriate precautions. While drugs are the mainstay of treatment for blood clots, certain patients may require a surgical procedure to prevent them.

Prescriptions

If you have or are suspected to have a blood clot, you'll likely leave your doctor's office with a prescription. What you take will depend on several factors, including your overall health, the probable cause of the clot, its severity, and more.

Anticoagulant Drugs

Anticoagulant drugs inhibit one or more of the clotting factors, a group of blood proteins that are responsible for blood clotting.

These drugs include:

  • Coumadin (warfarin): Until recently, warfarin was the only orally-administered anticoagulant drug available. The biggest problem with warfarin has been getting the dosage just right, which can be difficult for doctors and inconvenient for patients. When you start taking it, the dosage must be stabilized over a period of weeks, and frequent blood tests (INR blood tests) are necessary to assure this. Even after stabilization, INR tests need to repeat periodically and one's dosage of warfarin often requires re-adjustment. 
  • "New" Oral Anticoagulant Drugs: Because the optimal dose of warfarin can be relatively difficult to manage, drug companies have worked for years to come up with warfarin substitutes—that is, anticoagulant drugs that can be taken orally. Four of these new oral anticoagulant drugs (called the NOAC drugs) have now been approved. These are Pradaxa (dabigatran), Xarelto (rivaroxaban), Eliquis (apixaban), and Savaysa (edoxaban). The chief advantage of all these drugs is that they can be given in fixed daily dosages and do not require blood tests or dosage adjustments. However, as is the case with all drugs, there are downsides to the NOAC drugs
  • Heparin: Heparin is an intravenous drug that has an immediate (within seconds) inhibitory effect on the clotting factors. It is used exclusively in hospitalized patients. Doctors can adjust the dosage frequency, as needed, by monitoring the partial thromboplastin time (PTT) blood test. The PTT reflects how much the clotting factors have been inhibited (the "thinness" of the blood). 
  • Low Molecular Weight Heparin: These drugs, Lovenox (enoxaparin) and Fragmin (dalteparin), are purified derivatives of heparin. Their major advantage over heparin is that they can be given as injections (which almost anyone can learn to do in a few minutes) instead of intravenously, and they do not need to be closely monitored with blood tests. So, unlike heparin, they can be administered with relative safety on an outpatient basis.
  • Newer Intravenous or Subcutaneously-Administered Anticoagulant Drugs: Several heparin-like anticoagulant drugs have been developed, including argatroban, Angiomax (bivalirudin), Arixtra (fondaparinux), and Refludan (lepirudin). The optimal time and place to use all of these drugs are being slowly worked out.

    Anti-Platelet Drugs

    Three groups of drugs are used to reduce the "stickiness" of platelets, the tiny blood elements that form the nucleus of a blood clot. By inhibiting the ability of platelets to clump together, anti-platelet drugs inhibit blood clotting. These drugs are most effective in preventing abnormal blood clots from forming in arteries and are much less effective at preventing thrombosis in the veins. 

    • Aspirin and Aggrenox (dipyridamole): These drugs have a modest effect on platelet "stickiness" but cause fewer bleeding-related adverse effects than the other antiplatelet drugs. They are often used in an attempt to reduce the risk of heart attack or stroke in people whose risk is elevated. Aspirin is available over-the-counter (OTC) and in prescription form. Your doctor will tell you which one is appropriate for you. 
    • Ticlid (ticlopidine), Plavix (clopidogrel), and Effient (prasugrel): These drugs are more powerful (and therefore riskier) than aspirin and dipyridamole. They are commonly used when the risk of arterial clotting is especially high. Their most common application is in people who have received coronary artery stents, though decisions about when and how long to use them have been controversial.
    • IIb/IIIa Inhibitors: ReoPro (abciximab), Integrilin (eptifibatide), and Aggrastat (tirofiban): These drugs are the most powerful group of platelet inhibitors. They inhibit a namesake receptor on the surface of platelets that is essential for platelet stickiness. They are mainly used to prevent acute clotting after interventional procedures (such as angioplasty and stent placement) and to treat people with acute coronary artery syndrome. These drugs are very expensive and, in general, must be given intravenously.

      Thrombolytic Drugs

      These powerful drugs, also known as fibrinolytic agents or "clot busters," are given intravenously to dissolve blood clots that are in the process of forming. For the most part, their use is limited to patients who are within the first few hours of an acute heart attack or stroke in an attempt to re-open a blocked artery and prevent permanent tissue damage. 

      These drugs can be tricky to use and they carry a substantial risk of bleeding complications. However, in the right circumstances, these medications can prevent death or disability from a heart attack or stroke.

      Thrombolytic drugs include:

      • Tenecteplase: In the United States, this is currently the drug of choice because it appears to cause fewer bleeding consequences and is easier to administer than the other drugs in this group.
      • Streptokinase: This is used most frequently worldwide because it is relatively cheap.
      • Urokinase
      • Alteplase
      • Reteplase
      • tPA (tissue plasminogen activator)

      Surgeries

      Sometimes a blood clot in the arms or legs (called deep vein thrombosis, or DVT) can travel to the lungs, forming a blood clot called a pulmonary embolism (PE).

      For patients who are at risk of DVT and cannot take the available medications, other treatment is available. Surgeons can implant a small metal device called an inferior vena cava filter (IVC) that traps large clot fragments and prevents them from traveling through the vena cava (a large vein in the abdomen that brings blood from the lower body back to the heart).

      These filters can remain in place permanently or be removed depending on the individual patient's situation.

      Over-the-Counter Therapies

      If you have experienced or are at risk of a blood clot in your legs, your doctor may recommend you wear special elastic socks called compression stockings. These can help increase blood flow out of the legs and back to the heart, and reduce pain and swelling in the legs or arms due to damaged blood vessels, a condition known as post-thrombotic syndrome. 

      Compression stockings are available at drugstores and medical supply stores. Talk with your doctor about which length (knee-high or thigh-high) is best for you.

      How to Prevent Blood Clots
      Was this page helpful?
      View Article Sources