Once daily versus twice daily enoxaparin for acute pulmonary embolism in cancer patients.

Background: Venous thromboembolism (VTE) is a condition in which a thrombus occludes the vasculature. The incidence of VTE in cancer patients is three times higher than that of the general population. Enoxaparin 1 mg/kg subcutaneously (SC) twice daily and enoxaparin 1.5 mg/kg SC once daily are both FDA-approved dosing regimens for the treatment of pulmonary embolism (PE). The objectives of this study were to assess outcomes of cancer patients treated with once or twice daily enoxaparin for acute PE. Primary outcomes included recurrent or worsening PE and secondary outcomes included mortality or signs of clinically overt, major bleeding.

Methods: This study was a retrospective chart review of adult cancer patients treated at The University of Texas MD Anderson Cancer Center from 2011 to 2013 who received either 1 mg/kg twice daily or 1.5 mg/kg once daily enoxaparin for acute PE upon discharge.

Results: Among 48 patients in each the twice daily and once daily group, six recurrent PEs occurred. The incidence of recurrent PE was higher in the once daily group (n = 4) versus twice daily group (n = 2). More major bleeding events occurred in the once daily group than the twice daily group (15% vs. 6%). Mortality at 6 months was higher in the twice daily group versus once daily group (13% vs. 6%).

Conclusion: Cancer patients receiving once daily enoxaparin for the treatment of acute PE may be at increased risk of recurrent PE and clinically overt bleeding. Larger randomized trials are needed to confirm the results of this study.