Warfarin Calculators 🩸
Use these calculators to assess bleeding risk and dosing for patients on Warfarin.
Tools Included
- Warfarin – Bleeding & Reversal Tool
- Warfarin – Dosing Tool
- Review warfarin topic below for more information and guidance on warfarin management
- Education only — always follow local hospital / anticoagulation clinic protocol.
Warfarin Bleeding & Reversal Tool
For trained clinicians. Always follow local/hospital protocols.
Bleeding Risk Factors
Higher risk when INR >5:
- Age >70
- Previous bleeding complications
- GI ulcers/haemorrhage
- Prior CVA
- Recent surgery
- Uncontrolled blood pressure
- Recent initiation of anticoagulants
Reversal Plan
Additional Information
No-bleed INR adjustments follow the UNMH maintenance nomogram (target 2–3). Major bleed / ICH / urgent procedure reversal follows Irish PCC practice (e.g. Octaplex®) — always use your hospital haematology protocol.
Most over‑anticoagulated patients return to therapeutic range within ~3 days of stopping warfarin.
Monitor: repeat INR per above; more frequent if PCC given (30–60 min, ~6 h, then as guided).
Discuss prosthetic valve cases with cardiology/haematology before vitamin K or full reversal.
Warfarin Dosing Tool
Initiation & maintenance (UNMH nomogram; target INR 2–3 / 2.5–3.5)
Dosing Plan
Based on the UNMH Warfarin Dosing Guideline (initiation Days 1–6 and maintenance ≥1 week). Guidance only — individualise to the clinical scenario and follow local anticoagulation clinic policy.
Prefer home tablet strength at discharge; if changed, counsel and update pharmacy records. Before adjusting maintenance dose, check adherence, illness, drug interactions, and diet.
Educational reference only. Medical disclaimer