Anticoagulants and reversal

Warfarin Reversal There are guidelines. Look them up each time INR <4.5 without bleed Reduce or omit next dose INR 4.5-10 without bleed Withold warfarin 1-2mg vit K orally Repeat INR in 24-48 hours INR >10 without bleed Vit K 3-5mg oral/IV Consider PCC if high risk Repeat INR 12-24 hours

Bleeding Major bleed, INR >1.5 Significant bleed and INR >2 Intracranial, spinal, life threatening PCC 50iu/kg 150-300mL FFP (15mL/kg if PCC unavailable) Vit K 5-10mg IV Significant bleed and INR >2 PCC 35-50iu/KG dependent on INR Minor bleed 1 unit FFP Vit K 1-2mg orally or 0.51mg IV if INR >4.5 or bleeding risk high

Vitamin K Slow – several hours to take effect Don’t give more than you need – makes restarting warfarin very difficult Don’t give IM

Fresh frozen plasma Acute reversal in active bleeding Dose is 1 unit if PCC used, 4 units if not (to start) Has native INR 1.5 Does not fully replace factor IX Has factor VII which Prothrombinex does not Slow to get Large volume

Prothrombin complex concentrate Freeze dried factors II, IX, X Very small amount of factor VII PCC and FFP together will reverse warfarin in ~15 minutes Target INR Current INR Dose (IUnits/kg) Normalisation 1.5 - 2.5 30   2.6 - 3.5 35 ≥ 3.6 50 1.4 - 2.0 15 25 3.6 - 10 >10 40 Dose calculator

Dabigatran Direct thrombin inhibitor Behaves like a drug T ½ 14-17 hours, longer in renal failure APTT best for measurement – OK if normal Reversal – ?? PCC does not seem to work aPCC (FEIBA) might be better – but we don’t have any Can be dialysed

Rivaroxaban/Apixaban Factor X antagonist Also like a drug T1/2 7-14 hours – more with rivaroxaban in renal failure. APTT and PT prolonged Reversal with PCC – 50iu/kg, weak evidence. Protein bound, cannot be dialysed

NOACS and Coags Parameter Apixaban Dabigatran Rivaroxaban PT Prolonged No effect APTT Prolonged (1.4-1.8 times normal for therapeutic levels) Prolonged (1.5-1.8 times control) Thrombin time INR Not useful