Prothrombin complex concentrate for the urgent reversal of warfarin. Assessment of a standard dosing protocol.

Background: Octaplex®, a six factor prothrombin complex concentrate (PCC), has recently been approved for use in Canada. The optimal dose of Octaplex has yet to be established and our study was designed to monitor the efficacy of a low standard dose.

Study Design And Methods: Patients on warfarin treatment in need of urgent reversal for bleeding, invasive procedures or surgery were given a standard dose of 40 ml (1000 IU FIX, 14 IU/kg). We conducted a retrospective chart review of 231 patients.

Results: Patients given concurrent frozen plasma (FP) for reversal were eliminated from the study. Overall, 150 patients were reviewed and divided into three groups: (1) non-CNS bleeders, (2) CNS bleeders, and (3) non-bleeders. Correction of INR to 1.5 or less was achieved to the same extent in each group. Patients with active bleeding had the least successful bleeding cessation and patients with intracranial bleeding had the most dismal outcome compared to non-intracranial bleeders.

Conclusions: Our data suggests that Octaplex, when given as a low standard dose is effective at INR reversal with 76% of our patients correcting to an INR of 1.5 or less. It appears that this dose is sufficient for non-bleeding patients. Bleeding patients may benefit most from a dose increase to achieve more complete reversal and patients with intracranial bleeding should achieve more complete reversal within 2h of presentation.