Subcutaneous enoxaparin once or twice daily compared with intravenous unfractionated heparin for treatment of venous thromboembolic disease.

BACKGROUND

Low-molecular-weight heparins administered subcutaneously once or twice daily have been reported to be as safe and efficacious as intravenous unfractionated heparin in the treatment of acute venous thromboembolic disease.

OBJECTIVE

To determine whether subcutaneous enoxaparin administered once or twice daily is as effective as continuously infused unfractionated heparin in acute symptomatic venous thromboembolic disease.

DESIGN

Randomized, controlled, partially blinded equivalence trial.

SETTING

74 hospitals in 16 countries.

PATIENTS

900 patients with symptomatic lower-extremity deep venous thrombosis, including 287 (32%) with confirmed pulmonary embolism.

INTERVENTIONS

Initial therapy with dose-adjusted intravenous unfractionated heparin compared with subcutaneous enoxaparin at fixed dosages of 1.0 mg/kg of body weight twice daily or 1.5 mg/kg once daily. Long-term oral anticoagulation was started in all patients within 72 hours of randomization.

MEASUREMENTS

Clinical end points assessed during a 3-month follow-up period.

RESULTS

Equivalent efficacy was seen in the heparin group and both enoxaparin groups. Symptomatic venous thromboembolism recurred in 12 of 290 patients receiving unfractionated heparin (4.1%), 13 of 298 patients receiving once-daily enoxaparin (4.4%), and 9 of 312 patients receiving twice-daily enoxaparin (2.9%). Compared with unfractionated heparin, the treatment difference was 0.2% (95% CI, -3.04% to 3.49%) for once-daily enoxaparin and -1.2% (CI, -4.2% to 1.7%) for twice-daily enoxaparin. Incidence of major hemorrhage did not differ among the three treatment groups. Major hemorrhage occurred in 6 of 290 patients (2.1%) in the unfractionated heparin group, 5 of 298 patients (1.7%) in the once-daily enoxaparin group, and 4 of 312 patients (1.3%) in the twice-daily enoxaparin group.

CONCLUSIONS

Subcutaneous enoxaparin once or twice daily is as effective and safe as dose-adjusted, continuously infused unfractionated heparin in the prevention of recurrent symptomatic venous thromboembolic disease.