From the Guidelines
For patients with pulmonary embolism (PE) who have heparin-induced thrombocytopenia (HIT), argatroban is generally preferred over bivalirudin due to its more extensive clinical experience in HIT, FDA approval for this indication, and predictable hepatic clearance. Argatroban is typically initiated at 2 mcg/kg/min as a continuous IV infusion, adjusted to maintain an aPTT of 1.5-3 times baseline (not to exceed 100 seconds) 1. Bivalirudin can be used as an alternative, typically dosed at 0.15-0.2 mg/kg/hr, but may be preferred in patients with significant liver dysfunction, although it requires dose adjustment in renal impairment 1. Dose reduction is necessary for hepatic impairment (starting at 0.5-1.2 mcg/kg/min) 1. Both medications require close monitoring of aPTT levels, with checks typically performed 2 hours after initiation and after any dose changes. When transitioning to oral anticoagulation, warfarin should be overlapped with the direct thrombin inhibitor for at least 5 days and until the INR is therapeutic (2-3) for two consecutive days, with awareness that argatroban artificially elevates the INR 1. Key considerations in choosing between argatroban and bivalirudin include the patient's renal and hepatic function, as well as the specific clinical context, such as the need for urgent cardiac surgery or the presence of severe HIT 1. In general, the choice between argatroban and bivalirudin should be guided by the most recent and highest-quality evidence, with a focus on minimizing morbidity, mortality, and improving quality of life for patients with PE and HIT 1.
Some key points to consider:
- Argatroban has more extensive clinical experience in HIT and is FDA-approved for this indication 1.
- Bivalirudin may be preferred in patients with significant liver dysfunction but requires dose adjustment in renal impairment 1.
- Both medications require close monitoring of aPTT levels and dose adjustments as needed 1.
- The choice between argatroban and bivalirudin should be guided by the most recent and highest-quality evidence, with a focus on minimizing morbidity, mortality, and improving quality of life for patients with PE and HIT 1.
From the Research
Anticoagulation in Pulmonary Embolism Management
- Argatroban and bivalirudin are direct thrombin inhibitors used for anticoagulation in patients with heparin-induced thrombocytopenia (HIT) 2, 3, 4, 5.
- Both agents have been shown to be effective in achieving therapeutic anticoagulation in patients with suspected or confirmed HIT 4, 5.
Comparison of Argatroban and Bivalirudin
- A study found that argatroban may be advantageous compared to bivalirudin in achieving initial therapeutic anticoagulation goals among patients with suspected or confirmed HIT, with an average time to initial therapeutic anticoagulation of 4.71 hours for argatroban and 9.8 hours for bivalirudin (P < .01) 4.
- Another study reported that bivalirudin may be an effective and safe alternative option for the treatment of both suspected and confirmed HIT, with a low rate of new thrombosis (4.6%) and major bleeding (7.6%) 5.
Safety and Efficacy
- Argatroban has been shown to be safe and effective in patients with HIT, with a low risk of major bleeding (0-10% in the non-interventional setting and 0-5.8% periprocedurally) 2.
- Bivalirudin has also been shown to be safe and effective in patients with HIT, with a low risk of new thrombosis and major bleeding 5.
- However, a significant increase in major bleeding risk was found in critically ill patients treated with bivalirudin (13.1%; odds ratio 2.4,95% confidence interval 1.2-4.9, P = 0.014) 5.
Dosing and Monitoring
- The recommended initial dose of argatroban is 2 microg/kg/min, adjusted to achieve activated partial thromboplastin time (aPTT) values 1.5-3.0 times baseline 2, 6.
- The dosing of bivalirudin is not explicitly stated in the provided studies, but it is recommended to monitor aPTT values to ensure therapeutic anticoagulation 5.