Things We Do for No Reason™: Routine use of unfractionated heparin for initial anticoagulation in venous thromboembolism.

Venous thromboembolism is common among hospitalized patients. Current guidelines recommend direct oral anticoagulants and low-molecular-weight heparin (LMWH) as first-line therapy for most patients based on superior efficacy and ease of use. Compared with unfractionated heparin (UFH), LMWH provides more predictable anticoagulation, achieves therapeutic levels rapidly with weight-based dosing, and requires minimal laboratory monitoring. Randomized trials and observational studies demonstrate that LMWH is associated with lower rates of recurrent venous thromboembolism (VTE), bleeding, and heparin-induced thrombocytopenia. For most patients requiring parenteral anticoagulation, routine use of UFH should be avoided in favor of LMWH.