Four-factor prothrombin complex concentrate dose response relationship with INR for warfarin reversal

For reversal of warfarin-induced coagulopathy, FDA labeling of four-factor prothrombin complex concentrate (4F-PCC) endorses a dosing strategy based on body weight and baseline INR. Recent literature suggests lower, fixed doses of 4F-PCC may be equally efficacious. The present evaluation aims to characterize the relationship between 4F-PCC dose and degree of reduction in INR.

This is a retrospective, single-center review of 4F-PCC administrations for warfarin reversal between May 2014 and August 2017. The primary endpoint evaluates the relationship between doses of 4F-PCC and INR measurement after reversal, represented as a linear regression. Exploratory endpoints characterize the relationships of both body weight and baseline INR, the components determining initial 4F-PCC dose, with INR after reversal. Additionally, for records presenting with an INR of 2-3.9, mean INR after reversal was characterized as a function of two 4F-PCC dose cohorts (< 30 and ≥30 IU fIX/kg).

A significant linear relationship between 4F-PCC dose and INR after reversal (INR after 4F-PCC = 1.3651-0.00004(4F-PCC Dose), p = 0.0071, R² = 0.0630) was observed. Body weight and baseline INR were not correlated with INR after reversal. The subgroup analysis of records with presenting INR of 2-3.9 demonstrated no difference in mean INR after reversal with 4F-PCC for those receiving <30 IU fIX/kg and those receiving ≥30 IU fIX/kg.

This evaluation found no clinically relevant relationship with 4F-PCC doses and degree of INR reversal. Further prospective study is required to determine optimal dosing schemes of 4F-PCC for warfarin reversal.