The Vascular Disease Foundation defines deep vein thrombosis, or DVT, as a blood clot that develops in the large deep veins of the pelvic area or the extremities. DVTs can dislodge and travel to the blood vessel in the lungs, blocking blood flow and resulting in a pulmonary embolism, or PE. A massive clot blocking a major blood vessel or a treatment delay can prove fatal. Goals for the treatment of DVT include preventing spread or recurrence of the clot, and avoiding the occurrence of PEs.
Non-pharmacologic Measures
In the June 2004 issue of "American Family Physician," Dr. Dino Ramzi reported that very few studies support the use of non-pharmacologic measures in the treatment of DVT. Such measures include limitation of activities for several days, elevation of the affected leg, use of heat compresses and use of compression stockings. To reach the goals of therapy, however, anticoagulants, or blood thinners, are usually started. These drugs decrease the ability of the blood to clot.
Unfractionated HeparinHeparin
Unfractionated heparin is typically used in the hospital setting as a continuous intravenous anticoagulant, which means it helps prevent the formation of blood clots. Its use requires frequent monitoring of blood levels to ascertain that the blood-thinning effect remains at the therapeutic level. Too much thinning can cause uncontrollable bleeding, but too little may lead to inadequate treatment.
Unfractionated heparin also works as a subcutaneous injection, or a shot placed just beneath the skin. A patient receives the drug at least twice a day, with dose adjustments based on a set of blood parameters. The frequency of dosing and the meticulous monitoring it requires limits the use of unfractionated heparin to the acute care setting despite its affordability.
Low Molecular Weight Heparin
Low molecular weight heparin, or LMWH, includes enoxaparin and dalteparin. This drug is given on a daily, fixed dose as a subcutaneous injection. The substantially lower risk of bleeding associated with its use decreases the need for monitoring, making it more suitable for use in the outpatient setting. The use of LMWH has gained popularity for the initial treatment of DVT, but it is also appropriate for long-term use in cases where warfarin is contraindicated, such as during pregnancy.
Warfarin
All the drugs mentioned above are used for short-term, while warfarin is the oral anticoagulant of choice for long-term DVT treatment. Therapy can last anywhere from three months to a lifetime, depending on the cause of the DVT. The use of warfarin still requires frequent monitoring, but this changes from daily to once monthly as treatment progresses. Bleeding remains the major risk when using warfarin.
