Prothrombin complex concentrate for emergent reversal of warfarin: an international survey of hospital protocols

Weight-Based Dosing Versus a Fixed-Dose Regimen of 4-Factor Prothrombin Complex Concentrate in Obese Patients Requiring Vitamin K Antagonist Reversal

INTRODUCTION

Despite an increase in the use of fixed-dose protocols of 4-factor prothrombin complex concentrate (4F-PCC) for the reversal of vitamin K antagonists (VKAs), there remains a paucity of data in obese patients. In this study, we aimed to compare the proportion of patients attaining international normalized ratio (INR) goals using a weight-based dosing strategy versus a fixed-dose regimen of 4F-PCC.

METHODS

This was a retrospective study conducted in patients 18 years of age or older, weighing ≥ 100 kg, who received either a weight-based dose or fixed dose of 4F-PCC (2000 units) for the reversal of VKA, and had a documented baseline and post-treatment INR. The primary outcome was the proportion of patients achieving an INR of < 2 for all indications of warfarin reversal, except in patients with intracranial hemorrhage, where the goal was an INR of < 1.5.

RESULTS

A total of 44 patients met the inclusion criteria; 25 patients in the weight-based dosing group and 19 patients in the fixed-dose group. The median baseline INR was similar in both groups (weight-based dosing group 3.2 [interquartile range {IQR} 2.8-3.7] vs fixed-dose group 3.0 [IQR 2.7-4.9], p = 1). The median post-treatment INR was significantly lower in the weight-based dosing group compared to the fixed-dose group (1.3 [IQR 1.2-1.5] vs 1.6 [IQR 1.5-1.9], p < 0.01). However, there was no significant difference in the primary outcome between both groups (weight-based dosing strategy 84% vs fixed dose strategy 90%, p = 0.68).

CONCLUSION

Our findings suggest that a fixed-dose regimen of 2000 units in obese patients weighing ≥ 100 kg is adequate to achieve these INR goals.

Optimal Dosage and Administration Practices for Vitamin K Antagonist Reversal With 4-Factor Prothrombin Complex Concentrate

Expert consensus and international guidelines recommend urgent co-administration of vitamin K and 4-factor prothrombin complex concentrates (4F-PCCs) to rapidly reverse VKA-related bleeding. This narrative review examined real-world evidence and strategies to optimize international normalized ratio (INR) reversal, hemostasis, and outcomes in patients receiving 4F-PCC in this setting. Key determinants for success include the appropriate use of alternative dosing and administration strategies, such as fixed dosing and increased infusion speed, adherence to institutional guidelines, and removing significant institutional barriers to reduce time to treatment. In the opinion of authors, minimizing the time to treatment with 4F-PCCs is of paramount importance when treating patients with VKA-related bleeding. Practices that safely and feasibly shorten the time to administration should be included in guidelines for institutions responsible for anticoagulant care, and adhered to in centers that perform invasive procedures on patients receiving VKA therapy. Further studies are required to optimize use of 4F-PCC, particularly in relation to the ideal dosing strategy and the role of INR.

Emergency intensive care unit pharmacist's intervention may reduce time to four-factor prothrombin complex concentrate administration: a retrospective study

Background

Four-factor prothrombin complex concentrate (4F-PCC) must be administered as soon as possible, and in our emergency intensive care unit (EICU), pharmacists are available on weekdays for consultation on expediting 4F-PCC administration. Although recent reports have described a reduction in time to 4F-PCC administration, few studies have addressed if this is because of EICU pharmacist’s intervention, and there are no such studies in Japan. Therefore, we aimed to examine whether EICU pharmacist’s intervention reduced time to 4F-PCC administration.

Methods

This single-center retrospective cohort study was conducted from December 2017 to May 2019. We enrolled patients who received 4F-PCC due to major bleeding or requirement of urgent surgical/invasive procedures (n = 10). Patients were divided into two groups, namely, the intervention group (n = 5), in which EICU pharmacists consulted on weekdays, and the nonintervention group (n = 5), in which an intervention was not possible because of the absence of the EICU pharmacist.

Results

The median time from patient presentation to the EICU to 4F-PCC administration (103 min vs. 111 min, p = 0.4) was similar between the two groups; however, the median time from 4F-PCC prescription ordering to administration was significantly shorter in the intervention group than in the nonintervention group (21 min vs. 60 min, p = 0.02).

Conclusions

EICU pharmacist’s intervention improves the process from 4F-PCC prescription to administration and can reduce time to 4F-PCC administration.

Fixed-Dose Four-Factor Prothrombin Complex Concentrate for Vitamin K Antagonist Reversal: Does One Dose Fit All?

Four-factor prothrombin complex concentrate (4F-PCC) has emerged as the preferred option for emergent reversal of vitamin K antagonists (VKAs); however, the optimal dosing strategy is unknown. Although several studies have attempted to determine the optimal dose of 4F-PCC using a variety of dosing regimens, no dosing strategy has been found to be superior. Many of these studies have evaluated a low, fixed dose of 4F-PCC rather than individualized dosing as recommended in product labeling. The purpose of this review was to evaluate the efficacy and safety of various fixed-dose strategies of 4F-PCC for emergent VKA reversal and to assess limitations of the existing literature. A search of the PubMed database was performed from the earliest available date through 2018 for relevant articles describing fixed-dose 4F-PCC for VKA reversal. Reference lists of relevant articles were also manually reviewed. Most currently available studies are primarily observational and heterogeneous in design. A very low fixed dose of 500 IU is likely inadequate for successful VKA reversal, but increased fixed doses of 1000-1500 IU have found some degree of success and may be considered for VKA reversal. However, many of these studies consistently identified a trend toward international normalized ratio (INR) reversal failure in patients presenting with high baseline INR values or intracranial hemorrhage, suggesting that higher 4F-PCC doses are needed in these patients. Available studies are underpowered to determine whether a dose-dependent association with thrombotic risk exists. Additional large, randomized studies are needed to determine the optimal dosing strategy and ascertain the role for fixed-dose 4F-PCC.

Fixed-dose 4-factor prothrombin complex concentrate: we don't know where we're going if we don't know how to get there

4-Factor Prothrombin Complex Concentrate (4F-PCC) is the standard-of-care intervention in patients with major bleeding taking oral vitamin K antagonists. Despite growing clinical experience with 4-FPCC, the optimal dosing strategy remains unclear. In balancing efficacy, safety, and cost of this treatment, many institutions have adopted a low, fixed-dose regimen, with average doses lower than that in the package insert. The fixed-dose 4F-PCC strategy is supported by the available observational studies and case reports; however, the current body of literature is highly heterogenous. The purpose of this narrative review is to address the advantages and shortcomings with clinical use of fixed-dose 4F-PCC, as well as limitations of the available literature. The heterogeneity of the current literature should guide future studies to support or refute this potentially life-saving intervention.