Prothrombin complex concentrates used alone in urgent reversal of warfarin anticoagulation

Prothrombinex-VF (a three-factor prothrombin complex concentrate) contains little factor VII. Therefore, the Warfarin Reversal Consensus Guidelines from 2004 published by The Australasian Society of Haemostasis and Thrombosis recommend that it be administered with fresh frozen plasma to reverse warfarin anticoagulation.

To evaluate the efficacy and safety of Prothrombinex-VF used alone in warfarin reversal.

Adult patients requiring urgent reversal of warfarin anticoagulation were defined as having achieved complete (target international normalized ratio (INR) <1.4) or partial reversal (target INR 1.4-2.0) of their anticoagulation. Prothrombinex-VF was given at doses of between 25 and 50 IU/kg based on the intent of reversal and an INR was obtained 30min post infusion.

A total of 50 patients (mean age 72years, range 32-85years) was included. The median initial INR in the complete reversal arm (n= 35) was 3.5 (range 1.7-20) with 91% achieving the target INR (mean 1.1, range 0.9-1.4). In the partial reversal arm (n= 15) the mean initial INR was 5.6 (range 2.5-12) with 93% achieving the target INR (mean 1.6, range 1.4-2.2). There were no adverse effects attributed to Prothrombinex-VF.

Prothrombinex-VF is very effective and safe when used alone to reverse warfarin anticoagulation. The supplementary use of fresh frozen plasma in these patients is not required. A review of the current Warfarin Reversal Consensus Guidelines is needed.