When is PCC preferred over FFP?

Four-factor PCC is the agent of choice for urgent reversal of major or life-threatening bleeding on warfarin because it works within minutes, needs no thawing, and delivers a small fixed volume. FFP is slower, requires a large volume, and carries volume-overload risk, so it is mainly used when PCC is unavailable.

How is the PCC dose calculated?

Manufacturer labelling bands the dose by the presenting INR: roughly 25 IU/kg for an INR of 2 to under 4, 35 IU/kg for an INR of 4 to 6, and 50 IU/kg for an INR above 6. The dose is capped near a maximum body weight (often 100 kg) and the vial total. This calculator reproduces those bands.

How much FFP is needed?

FFP for warfarin reversal is dosed at about 15 mL/kg. At a typical unit volume near 250 mL that is roughly one unit per 17 kg of body weight, so a 70 kg adult needs about 1050 mL, or four to five units. The large volume is why PCC is generally preferred.

Should vitamin K be given as well?

Yes. PCC and FFP only top up clotting factors temporarily, so intravenous vitamin K (typically 5 to 10 mg) must be co-administered to sustain reversal once the infused factors decline. Without vitamin K the INR rebounds within hours.

Is this a prescribing tool?

No. It is an educational calculator that reproduces common banding rules. Exact dosing depends on the specific product, local haematology and transfusion protocols, the indication, and the prescriber's judgement. Always confirm doses against the product label and local guidance.

INR Reversal — FFP or PCC Dose Calculator

Patients on warfarin who present with major bleeding or who need urgent surgery require rapid correction of their raised INR. The two mainstays are four-factor prothrombin complex concentrate (PCC) and fresh frozen plasma (FFP), each dosed by body weight and, for PCC, by the presenting INR.

How it works

Fresh frozen plasma is dosed by a simple weight rule:

FFP volume = 15 mL/kg
FFP units  = FFP volume / unit volume (~250 mL)

Four-factor PCC is dosed from an INR-banded weight rule that mirrors manufacturer labelling:

INR 2 to <4   -> 25 IU/kg
INR 4 to 6    -> 35 IU/kg
INR > 6       -> 50 IU/kg
dose = band x min(weight, 100 kg)

The body weight is usually capped near 100 kg and the dose by the maximum studied total. Both products are factor top-ups, so intravenous vitamin K must accompany them to keep the INR down once the infused factors wear off.

Notes and cautions

PCC corrects the INR within minutes and avoids the large volume load of FFP, which is why guidelines favour it for life-threatening bleeding. The banded doses here are the values most commonly quoted on PCC labels, but products differ and some centres use a fixed-dose strategy regardless of INR. FFP carries a real risk of transfusion-associated circulatory overload at the volumes required, particularly in older or cardiac patients. This calculator is for education and bedside cross-checking only; confirm every dose against the product label and local protocol.