Pharmacology
Warfarin Reversal (INR)
Vitamin K antagonist reversal guidance by INR and bleeding.
Warfarin Reversal (INR) calculator
Result
INR 4.5
Supra-therapeutic INR. Reduce dose or withhold. Identify precipitant (drugs, diet, illness).
How to use it
- 1
Stratify by bleeding severity. Major: haemorrhagic stroke, haemothorax, retroperitoneal, haemodynamic compromise.
- 2
4F-PCC for urgent reversal. Beriplex, Octaplex: rapid reversal in minutes vs. FFP (hours, volume load).
- 3
Vitamin K takes 6–24h. Oral Vit K as effective as IV for non-urgent reversal, but slower. IV Vit K for emergency.
When to use it
- Supratherapeutic INR > 3 (target 2–3)
- Most common: drug interactions (antibiotics, NSAIDs), illness, dietary change.
- Reversal before urgent surgery
- Surgery within 6h: 4F-PCC. Within 24h: Vit K 5 mg IV. > 24h: Vit K 1–2 mg oral.
- AF re-anticoagulation
- After ICH reversal: bridge with heparin only when CHA₂DS₂-VASc risk outweighs ICH recurrence (typically 4–12 weeks).
A reference for clinicians and students, not medical advice. A score supports a decision; it does not make one. Check every result against the patient in front of you and your local protocol.
At a glance
- Specialty
- Pharmacology
- Inputs
- 2
- Type
- Formula
