Fixed dose 4-factor prothrombin complex concentrate for the emergent reversal of warfarin: a retrospective analysis

Published literature suggests that a fixed-dose 4-factor prothrombin complex concentrate (4FPCC) may be efficacious in managing warfarin-associated hemorrhage, however the ideal dose is still unclear. The purpose of this evaluation was to determine the efficacy of fixed-dose 4FPCC in reducing the International Normalized Ratio (INR) to ≤ 1.5 among warfarin patients with need for urgent or emergent anticoagulation reversal. Starting October 2016, our institution changed from standard 4FPCC FDA-labeled dosing based on the patient's presenting INR and weight, to a fixed-dose of 1500 units for all patients requiring urgent or emergent warfarin reversal. We conducted a retrospective evaluation, after implementation, with the primary outcome being the proportion of patients who achieved an INR ≤ 1.5 with a single fixed-dose of 1500 units of 4FPCC. Secondary outcomes assessed included: medication turnaround times, attainment of target INR ≤ 2 or clinical hemostasis (as judged by the prescribing provider), use of rescue doses, thrombotic events, and cost savings. A total of 37 patients were included in the analysis. Almost 75% of patients achieved an INR ≤ 1.5 after a single fixed dose of 1500 units, and 100% of patients achieved an INR ≤ 2. The median pre- and post-dose INRs were 3.06 and 1.32 respectively. Based on this evaluation, the administration of a fixed dose of 1500 units 4FPCC, was shown to be effective in adequately reversing the INR in the majority of patients with minimal thrombotic risks.