Risk of bleeding (risk factors include bacterial endocarditis, congenital or acquired bleeding disorders, active ulcerative or angiodysplastic gastrointestinal diseases, severe uncontrolled hypertension, hemorrhagic stroke, or use shortly after brain, spinal, or ophthalmologic surgery). Can cause hyperkalemia by affecting aldosterone. Caution in hypersensitivity to methylparaben or propylparaben. Rare cases of thrombocytopenia (use with extreme caution in history of heparin-induced thrombocytopenia) or thrombocytopenia with thrombosis (use caution in congenital or drug-induced thrombocytopenia or platelet defects) have occurred. Cancer patients with thrombocytopenia may require dose adjustments for treatment of acute venous thromboembolism. Caution in severe renal failure (not studied). Multidose vials may contain benzyl alcohol and should not be used in pregnant women. In neonates, large amounts of benzyl alcohol (>100 mg/kg/day) have been associated with fatal toxicity («gasping syndrome»). Not interchangeable with heparin or any other low molecular weight heparins. Patients with recent neuraxial anesthesia are at risk of spinal or epidural hematoma and subsequent paralysis (risk is increased by concomitant agents which may alter hemostasis, as well as traumatic or repeated epidural or spinal puncture).