From the Guidelines
Dabigatran and edoxaban must be initiated with low molecular weight heparin (LMWH) before their use in acute venous thromboembolism (VTE) treatment because they require a bridging period to ensure continuous anticoagulation coverage. This approach is based on the pharmacodynamic properties of dabigatran and edoxaban, which take time to reach therapeutic anticoagulation levels, creating a potential gap in protection during the acute phase of thrombosis when the risk of clot extension or embolization is highest 1. The typical protocol involves starting LMWH (e.g., enoxaparin 1 mg/kg twice daily) immediately upon diagnosis, continuing for at least 5 days, and then transitioning to either dabigatran 150 mg twice daily or edoxaban 60 mg once daily (with dose adjustments for renal impairment or low body weight) 1. Some key considerations for selecting an anticoagulant include:
- Patient requirements for medications that interact with direct oral anticoagulants (DOACs)
- Renal and/or hepatic insufficiency
- Cost of DOACs and patient preference for once- or twice-daily dosing
- Presence of conditions that may influence medication absorption, such as antiphospholipid antibody syndrome, bariatric surgery, short gut, or extremes of body weight 1. In contrast, rivaroxaban and apixaban can be started immediately at higher doses without the need for initial bridging with LMWH 1. The British Thoracic Society guideline also recommends treatment with LMWH and dabigatran or LMWH and edoxaban for patients with confirmed pulmonary embolism being treated in the outpatient setting 1. Overall, the use of LMWH as a bridging agent before initiating dabigatran or edoxaban is a crucial step in ensuring effective and safe anticoagulation therapy for patients with acute VTE.
From the Research
Initiation of Dabigatran and Edoxaban with LMWH
- Dabigatran and edoxaban are direct-acting oral anticoagulants (DOACs) that require initiation with low-molecular-weight heparin (LMWH) before their use 2.
- This is because LMWH is used as a bridging therapy to prevent thromboembolic events until the DOACs reach their therapeutic levels 2.
- The use of LMWH as a bridging therapy is a common practice in the treatment of venous thromboembolism (VTE) and is recommended by current guidelines 2, 3.
Rationale for Bridging Therapy
- The rationale for bridging therapy is to provide immediate anticoagulation with LMWH while waiting for the DOACs to reach their therapeutic levels 2.
- This is particularly important in patients with acute VTE, where the risk of recurrent thromboembolic events is high 2, 3.
- The use of LMWH as a bridging therapy has been shown to be effective in reducing the risk of recurrent VTE and is a recommended practice in current guidelines 2, 3.
Duration of Bridging Therapy
- The duration of bridging therapy with LMWH typically ranges from 5 to 10 days, depending on the specific DOAC being used and the patient's individual risk factors 2, 3.
- For dabigatran and edoxaban, the recommended duration of bridging therapy is at least 5 days, although this may vary depending on the patient's individual circumstances 2.
- It is essential to monitor the patient's laboratory parameters, such as the international normalized ratio (INR), to ensure that the DOAC has reached its therapeutic level before discontinuing the LMWH 2, 3.