Risks and benefits of low molecular-weight heparin and target-specific oral anticoagulant use for thromboprophylaxis in medically ill patients.

Venous thromboembolism is the third most common cardiovascular disease and a major cause of inpatient mortality as over 50 % of deep vein thrombosis and pulmonary embolism are undetected in medically treated patients. Several agents are approved for thromboprophylaxis, including warfarin, unfractionated heparin, low molecular-weight heparins, fondaparinux, and target-specific oral anticoagulants. The purpose of this literature review is to discuss the increased risk of venous thromboembolism in medically ill patients and the literature surrounding the efficacy and tolerability of low molecular-weight heparins and target-specific oral anticoagulants for this indication. PubMed, MEDLINE, EBSCOhost, and clinicaltrials.gov were used as search engines in the literature review. Search limits included articles containing human subjects, scholarly (peer-reviewed) journals written in English, and publication dates from 2004 to 2014. Animal studies, non-English articles, and publications dated prior to 2004 were excluded. Recurrent venous thromboembolism remains an ongoing problem affecting thousands of people in the non-surgical population annually. With limited data, it is not likely that target-specific oral anticoagulants will soon replace low molecular-weight heparins or even be considered an alternative until efficacy and tolerability have been established. Until further evidence is disclosed, low molecular-weight heparins and fondaparinux (in the absence of renal dysfunction and low body weight) should continue to be utilized as first-line agents for thromboprophylaxis in medically ill patients. The use of apixaban and rivaroxaban is discouraged for thromboprophylaxis in medically ill patients.