Appropriate enoxaparin dose for venous thromboembolism prophylaxis in patients with extreme obesity.

OBJECTIVE To evaluate the appropriate dose of enoxaparin for venous thromboembolism (VTE) prophylaxis in patients with extreme obesity. METHODS A literature search was performed using MEDLINE (1950-April 2013) to analyze all English-language articles that evaluated incidence of VTE and/or anti-Xa levels with enoxaparin for thromboprophylaxis in patients with extreme obesity. RESULTS Eight studies were included in the analysis. Six of the studies were done in patients undergoing bariatric surgery. Mean body mass index ranged from 44.9 to 63.4 kg/m(2) within studies. Studies done with bariatric surgery patients utilized doses of enoxaparin that ranged from the standard dose of 30 mg subcutaneous (SQ) every 12 hours to 60 mg SQ every 12 hours. Other studies evaluated doses ranging from 40 mg SQ every 24 hours to 0.5 mg/kg/day. Only 3 studies evaluated the incidence of VTE as the primary endpoint; the other studies evaluated anti-Xa levels. The studies showed that appropriate anti-Xa levels were achieved more often with higher than standard doses of enoxaparin. One study showed that enoxaparin 40 mg SQ every 12 hours decreased the incidence of VTE in patients undergoing bariatric surgery compared to standard doses. Overall risk of bleeding was similar between study groups. CONCLUSIONS Higher than standard doses of enoxaparin may be needed for patients with extreme obesity. Patients undergoing bariatric surgery may benefit from enoxaparin 40 mg SQ every 12 hours. Additional large randomized, controlled trials are needed to determine the efficacy and safety of higher than standard doses of enoxaparin for VTE prophylaxis in patients with extreme obesity.