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Updated: Dec 4, 2025

Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
Outcomes Associated With 4-Factor Prothrombin Complex Concentrate Administration to Reverse Oral Factor Xa Inhibitors
Emily A Highsmith1, Celia Morton1, Sara Varnado1
1Houston Methodist Hospital, Houston, Texas, USA.
Abstract:
Compared with vitamin K antagonists (VKAs), oral factor Xa inhibitors are associated with at least equivalent efficacy and a lower incidence of major bleeding. Despite this benefit, bleeding remains the most common adverse event. Prior to the approval of andexanet alfa, alternative agents such as 4-factor prothrombin complex concentrate (4F-PCC) were utilized for reversal. This was a retrospective, descriptive study conducted on patients 18 years of age or older who received 4F-PCC for reversal of oral factor Xa inhibitors-associated bleeding. Patients were excluded if they received a VKA or dabigatran in the previous 48 hours. A subgroup analysis comparing 4F-PCC with andexanet alfa was conducted on patients who met the inclusion and exclusion criteria of the ANNEXA-4 trial. The primary end point of this study was to evaluate the incidence of hemostasis and associated dosing strategies in patients receiving 4F-PCC for reversal of oral factor Xa inhibitors-associated bleeding. Thirty-eight patients were included, and 28 patients (74%) achieved hemostasis. The median dose of 4F-PCC was 50 units/kg. In patients who achieved hemostasis, the median dose was 50 units/kg, and in those who failed to reach hemostasis, a median dose of 30 units/kg was seen. Within the subgroup analysis, there was no difference in overall rates of hemostasis between the 4F-PCC and andexanet alfa groups. Remaining a reasonable option to utilize for reversal of oral factor Xa inhibitors is 4F-PCC, especially when andexanet alfa is unavailable, with 50 units/kg appearing to be the most effective dose to achieve hemostasis. Further studies are needed to determine a preferential agent.
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