Adjusted versus actual body weight dosing of 4-factor prothrombin complex concentrate in obese patients with warfarin-associated major bleeding

The package insert of 4-factor prothrombin complex concentrate (4F-PCC) contains specific dosing recommendations stating to determine the patients dose based on their INR and weight, capping the weight at 100 kg. However, the mean body mass index (BMI) in the 4F-PCC U.S. approval study was 27 kg/m², and there is a lack of literature identifying the ideal dosing strategy in obesity. We conducted a retrospective analysis of obese patients (BMI ≥ 30 kg/m²) who received 4F-PCC for warfarin associated emergent bleeding reversal. Treatment groups were those that received 4F-PCC on adjusted body weight (AdjBW) and those on actual body weight (ActBW). The primary outcome was the percent of patients achieving coagulopathy reversal, defined as a post-treatment INR < 1.4 for neurologic indications and < 1.5 for all others. A total of 78 obese patients were included (28 AdjBW and 50 ActBW). Baseline INR (3.1 vs. 2.8; p = 0.052) and BMI (33.6 vs. 33.6 kg/m²) were similar between groups. Achievement of goal INR was significantly lower in the AdjBW group (36% vs. 68%; p = 0.006). A majority of patients had intracranial hemorrhage (32% vs. 54%; p = 0.06), and the median dose of 4F-PCC was lower in the AdjBW group (2120 vs. 2500 units; p = 0.02). Dosing 4F-PCC using adjusted body weight in obese patients resulted in a significantly lower rate of coagulopathy reversal. ActBW should be used to dose 4F-PCC in obese patients when the 100 kg dose cap is utilized per the package insert recommendations.