Weight-based dosing Subcutaneous low molecular weight heparin has several advantages over unfractionated heparin including Superior bioavailability Weight-based dosing results in a more predictable anticoagulation effect than does weight-based dosing of unfractionated heparin Ease of administration (can be given subcutaneously once or twice a day) Decreased incidence of bleeding Potentially better outcomes The potential for patients to self-inject (thereby allowing earlier discharge from the hospital) Lower risk of heparin - induced thrombocytopenia compared with standard, unfractionated heparin In patients with renal insufficiency, dose reductions are needed (see table Some Low Molecular WeightHeparinOptions in Thromboembolic Disease), and subsequent verification of appropriate dosing should be done by checking serum factor Xa levels (target: 0.5 to 1.2 IU / mL measured at 3 to 4 hours after the 4th dose).