What Is the Medical Treatment for Blood Clots?
Depending upon their location, blood clots may be aggressively treated or may need nothing more than symptomatic care.
Venous thrombosis in the leg may occur in the superficial or deep systems of veins.
Clots in the superficial system are often treated symptomatically with warm compresses and acetaminophen or ibuprofen since there is no risk for clots in the superficial veins to embolize to the lung. They are connected to the deep system by perforator veins that have valves that act like a sieve to strain and prevent clots from traveling to the lung.
Deep venous thrombosis usually requires anticoagulation to prevent the clot from growing and causing a pulmonary embolus. Treatment tends to occur in an outpatient setting using medications that anticoagulate or "thin" the blood. There are a variety of medications available to treat blood clots.
- The American College of Chest Physicians has published guidelines regarding the type of blood thinners to be considered in the treatment of blood clots in the legs or in the lungs.
- In patients with DVT or PE and no active cancer, the drug of choice is a novel oral anticoagulant (NOAC), also known as a direct oral anticoagulant (DOAC) because of where they block the coagulation cascade to thin the blood.
- NOACs that block clotting Factor Xa include:
- apixaban (Eliquis)
- rivoroxiban (Xarelto)
- edoxiban (Savaysa)
- dabigatran is another NOAC that is a direct thrombin inhibitor.
- In patients with DVT or PE and active cancer, the recommended medication is low molecular weight heparin or enoxaparin (Lovenox).
- In unstable patients, or those where there is concern that they will become unstable in the near future, and who need hospitalization, the anticoagulation drug that is recommended is intravenous unfractionated heparin. When there is a large amount of blood clot in the pulmonary arteries, strain can be put on the heart and lung function and thrombolytic therapy with tissue plasminogen activator (tPA) drugs, so-called clot busting drugs, might be considered. These patients are usually critically ill and in shock.
- If there is massive amount of clot in the femoral or iliac veins, no blood may be able to leave the leg and it becomes massively engorged, swollen and blue. This is called phlegmasia cerulia dolens and may require treatment with tPA. Similar situations may occur in the arm with clots that form in the subclavian or axillary vein.
- Classically, warfarin (Coumadin) was most commonly used to treated blood clots. It is a vitamin K inhibitor and affects Factors II, VII, IX and X of the clotting cascade. Because it takes a few days to reach therapeutic levels, an injectable heparin product, (enoxaparin, fondaparinux) was also prescribed for the patient as a bridge to immediately thin the blood.
Blood clots below the knee are at lower risk for embolization to the lung, and an alternative to anti-coagulation treatment is serial ultrasound examinations to monitor the clot to see whether it is stable or growing.
Pulmonary emboli are treated similarly to deep venous thrombosis. In patients who have increasing shortness of breath or weakness, hospitalization may be required during the initial treatment phase. In certain situations, when there are large amounts of blood clot in the pulmonary arteries, strain can be put on the heart and lung function and thrombolytic therapy with tissue plasminogen activator (tPA) drugs, so-called clot busting drugs, might be considered. These patients are usually critically ill and in shock.
Arterial blood clots are often managed more aggressively. Surgery may be attempted to remove the clot, or medication may be administered directly into the clot to try to dissolve it. Alteplase (Activase, tPA) or tenecteplase (TNKase) are examples of clot busting medications that may be used in peripheral arteries to try to restore blood supply.
Heart attack: The same approach for heart attack is used as for arterial blood clots. If possible, cardiac catheterization is performed to locate the blocked blood vessel and a balloon is used to open it, restore blood flow, and a stent is placed to keep it open. This is a time-sensitive procedure and if a local hospital is unable to perform a heart catheterization emergently, within 60-90 minutes of the patient's arrival to medical care, thrombolytic medications described above like tPA or TNK may be used intravenously to try to dissolve the thrombus and minimize heart muscle damage. There will still be the need to eventually transfer the patient when stable to a hospital with the capability to perform heart catheterizations.
Stroke also is treated with tPA if the patient is an appropriate candidate for this treatment. Each patient is different and may or may not qualify for this medication with an acute stroke. Again, this is a time sensitive emergency and in addition to tPA, an interventional radiologist may be able to insert a catheter into the blood vessels of the brain, identify the clot and remove it, thus hopefully reversing the stroke.