The use of Lovenox for DVT would be off-label because it is only indicated for he outpatient treatment of acute deep vein thrombosis without pulmonary embolism when administered in conjunction with warfarin sodium. It is, however, a medically reasonable drug to use in this situation of intolerance to some of the most popular other options.
Dosage is another matter. In outpatient treatment, patients with acute deep vein thrombosis without pulmonary embolism who can be treated at home, the recommended dose of Lovenox is 1 mg/kg every 12 hours administered SC. In inpatient (hospital) treatment, patients with acute deep vein thrombosis with pulmonary embolism or patients with acute deep vein thrombosis without pulmonary embolism (who are not candidates for outpatient treatment), the recommended dose of Lovenox is 1 mg/kg every 12 hours administered SCor 1.5 mg/kg once a day administered SC at the same time every day. In both outpatient and inpatient (hospital) treatments, warfarin sodium therapy should be initiated when appropriate (usually within 72 hours of Lovenox). Lovenox should be continued for a minimum of 5 days and until a therapeutic oral anticoagulant effect has been achieved (International Normalization Ratio 2.0 to 3.0). The average duration of administration is 7 days; up to 17 days of Lovenox administration has been administered in controlled clinical trials.
Lovenox is often used at 1.5mg daily to avoid bid injections. However, the literature does not support this dose. US Food and Drug Administration-approved dosing of enoxaparin for prevention of deep venous thrombosis depends on the specific indication, and varies from 40 mg subcutaneously (SC) once daily to 30 mg SC every 12 hours for patients with normal renal function (1)) The American College of Chest Physicians (ACCP) advises clinicians to follow manufacturer recommendations for antithrombotic dosing.[2]
However, the guidelines do have a few “exceptions,” such as recommending use of higher-prophylaxis dosing in obese patients.[2] Interpreting what this “higher” dose is may be challenging. A recent reviewconcludes that nonpregnant, nonobese medical and surgical patients with a history of VTE who are not chronically anticoagulated should receive the same enoxaparin dose for VTE prophylaxis as those without a history of VTE.
In obese patients, weight-based dosing of low-molecular-weight heparins (LMWH) is recommended on the basis of data showing reduced anti-Xa levels with an increase in weight.[6] However, the optimal weight-based dose remains to be established. Suggested prophylactic enoxaparin regimens that are based on small studies in morbidly obese patients include 30% increases in usual LMWH dose, 40 mg SC every 12 hours, and 0.5 mg/kg SC once daily.[6-8] Additional consideration can be given to monitoring peak anti-Xa levels (4 hours post dose) with a goal of 0.2-0.4 IU/mL for VTE prophylaxis in obese patients.[6] However, this strategy requires further clinical review before becoming standard of care.