What is the initial treatment of DVT?
The initial treatment of both DVT and PE is anticoagulation. Anticoagulants, commonly referred to as “blood thinners,” do not actually thin blood. Instead, they block the action of various clotting factors and prevent blood clots from growing. In this way, they allow the body’s own natural processes to destroy clots over time.
In the last 10 years, the anticoagulants that have been used for the initial treatment of DVT and PE have changed somewhat. Rather than initial treatment with standard or “unfractionated” heparin, patients are often started on low-molecular-weight heparin (LMWH). Studies have shown that LMWH is at least as effective as standard heparin, but is more convenient to use and has fewer side effects. Compared to standard heparin, LMWH has a longer duration of action, so it requires only daily or twice-daily injections. LMWH also does not have to be directly administered into a vein (unlike standard heparin), but rather can be injected underneath the skin or subcutaneously, usually underneath the skin of the abdomen. Neither heparin nor LMWH can be given by mouth, however. Because LMWH is usually dispensed in prepared (already drawn-up) syringes, many patients with DVT do not require admission to the hospital for treatment. They (or another family member) can be taught how to give themselves injections of LMWH and, therefore, can avoid a hospital stay.
Three LMWHs have been approved by the U.S. Food and Drug Administration (FDA) for the prevention of DVT and PE: dalteparin (Fragmin®), tinzaparin (Innohep®), and enoxaparin (Lovenox®). Only two of these medications, tinzaparin and enoxaparin, have been approved for the treatment of DVT and PE.
Fondaparinux (Arixtra®) is a new type of anticoagulant that has been used for the prevention of DVT and PE and has recently been approved by the FDA for the treatment of DVT and PE. Like LMWH, it cannot be given by mouth or infused intravenously, but it can be given subcutaneously. Fondaparinux has an even longer duration of action than LMWH and requires only once-daily injections.