From the Research
For cardioversion in patients with atrial fibrillation, the recommended dose of Lovenox (enoxaparin) is 1 mg/kg subcutaneously twice daily, as supported by the Anticoagulation in Cardioversion using Enoxaparin (ACE) trial 1. This anticoagulation should be started at least 3 weeks before the cardioversion procedure and continued for at least 4 weeks afterward. For patients with atrial fibrillation lasting less than 48 hours, Lovenox can be given as a single dose of 1 mg/kg subcutaneously before the procedure. Some key points to consider when using Lovenox for cardioversion include:
- Kidney function affects dosing, and patients with severe renal impairment (creatinine clearance <30 mL/min) should receive a reduced dose of 1 mg/kg once daily, as seen in studies such as 2.
- Anticoagulation before cardioversion is crucial to reduce the risk of thromboembolism, as the restoration of normal rhythm can dislodge clots that may have formed in the atria during fibrillation.
- The therapeutic effect of Lovenox begins within 3-5 hours of administration, making it suitable for urgent cardioversion when needed.
- After the initial period of anticoagulation, patients should be evaluated for long-term oral anticoagulation based on their stroke risk factors. It's also important to note that while some studies have compared enoxaparin to unfractionated heparin in terms of safety and efficacy for preventing thromboembolic complications in cardioversion, such as 3 and 4, the most relevant and recent guidance for dosing comes from studies focused on the specific context of cardioversion and renal function, like 1 and 2.