From the Guidelines
Switching from Fragmin (dalteparin) to Lovenox (enoxaparin) is generally not recommended when a patient develops a pulmonary embolism (PE) while already on Fragmin, as the most recent and highest quality study suggests optimizing the current anticoagulation therapy instead 1. The preferred approach is to ensure the patient is receiving the appropriate weight-based dose of Fragmin, confirming medication adherence, and considering a more potent anticoagulant. For patients who develop a PE while on properly dosed low molecular weight heparin (LMWH) like Fragmin, escalation to a direct oral anticoagulant (DOAC) or warfarin with a heparin bridge may be necessary, as recommended by the 2019 ESC guidelines for the diagnosis and management of acute pulmonary embolism 1. In some cases, particularly for cancer-associated thrombosis, increasing the Fragmin dose by 20-25% might be appropriate, as suggested by the American Society of Clinical Oncology clinical practice guideline update 1. The rationale is that switching between different LMWHs (Fragmin to Lovenox) doesn't address the underlying issue of anticoagulation failure, as they work through similar mechanisms. Additionally, consider investigating potential causes for anticoagulation failure, such as cancer progression, antiphospholipid syndrome, or heparin-induced thrombocytopenia, and consultation with a hematologist is advisable for these complex cases of recurrent thrombosis despite anticoagulation 1. Some key points to consider include:
- Optimizing the current anticoagulation therapy with Fragmin
- Considering a more potent anticoagulant, such as a DOAC or warfarin with a heparin bridge
- Investigating potential causes for anticoagulation failure
- Consulting with a hematologist for complex cases
- Following the most recent and highest quality guidelines, such as the 2019 ESC guidelines 1 and the American Society of Clinical Oncology clinical practice guideline update 1.
From the Research
Treatment of Pulmonary Embolism with Lovenox
- When a patient develops a pulmonary embolism (PE) while on Fragmin (dalteparin), treatment with Lovenox (enoxaparin) may be considered as an alternative anticoagulant therapy 2, 3.
- Low molecular weight heparins (LMWH) such as enoxaparin and dalteparin are preferred over unfractionated heparin (UFH) in the initial anticoagulation of PE due to their lower risk of bleeding 2.
- The decision to switch from dalteparin to enoxaparin should be based on individual patient factors, such as renal function, body weight, and bleeding risk 3.
- Enoxaparin has been shown to be effective in reducing the risk of recurrent venous thromboembolism (VTE) and is a commonly used alternative to UFH for VTE prophylaxis in intensive care units 4.
Clinical Considerations
- Patients with high or intermediate clinical probability of PE should be initiated on anticoagulation without delay while awaiting diagnostic test results 2.
- The duration of anticoagulation should be individualized based on the patient's risk of PE recurrence and bleeding risk 2, 5.
- Direct oral anticoagulants (DOACs) such as apixaban, edoxaban, and rivaroxaban are effective alternatives to LMWH and vitamin K antagonists (VKAs) for long-term anticoagulation in patients with PE 2, 3.