Hypersensitivity. Clinically significant active bleeding; lesion or condition considered to be significant risk for major bleeding eg, current or recent GI ulceration, presence of malignant neoplasms at high risk of bleeding, recent brain or spinal injury, recent brain, spinal or ophth surgery, recent intracranial haemorrhage, known or suspected oesophageal varices, AV malformations, vascular aneurysms or major intraspinal or intracerebral vascular abnormalities; uncontrolled severe HTN. Concomitant use w/ any other anticoagulants eg, unfractionated heparin (UFH), LMWH (enoxaparin, dalteparin), heparin derivatives (fondaparinux), oral anticoagulants (warfarin, dabigatran etexilate, rivaroxaban, apixaban) except under specific circumstances of switching oral anticoagulants therapy or when UFH is given at doses necessary to maintain open central nervous or arterial catheter. Hepatic disease associated w/ coagulopathy & clinically relevant bleeding risk. Pregnancy & lactation.