🩸 Warfarin & INR Management
Warfarin reference: target INR by indication, high-INR and bleeding management per ACCP/CHEST, interactions and missed-dose advice. Browser-side.
Serious bleeding: stop, IV vitamin K + 4-factor PCC (or FFP), haematology consult.
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When to use
Bedside reminder of INR targets and how to manage a supratherapeutic INR or bleeding. Specific vitamin K/PCC doses follow institutional protocol.
How it works
Target INR 2.0–3.0 for most indications; 2.5–3.5 for mitral mechanical valves/high-risk. INR > 10 without bleeding: hold + oral vitamin K 2.5–5 mg.
Key points
- Serious bleeding: stop, IV vitamin K + 4-factor PCC (or FFP), haematology consult.
- Many antibiotics, amiodarone and azoles raise INR; rifampin and enzyme inducers lower it.
- Missed dose: take that day's dose when remembered; do not double up.
- Monitor every 4 weeks once stable; recheck 1–2 weeks after dose changes.
References
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| View | Target INR |
|---|
→Key pointTarget INR
- Most indications：2.0–3.0 (AF, VTE, first 3 months after a bioprosthesis, low-risk aortic mechanical valve)
- Mitral mechanical valve / high-risk：2.5–3.5
- Monitoring：Every 4 weeks once stable; recheck 1–2 weeks after a dose change
| View | Interactions & missed dose |
|---|
→Key pointInteractions & missed dose
- Raise INR：Amiodarone, metronidazole, trimethoprim-sulfamethoxazole, azoles, many antibiotics, acute alcohol/liver disease, low vitamin K intake
- Lower INR：Rifampin, carbamazepine, phenytoin, barbiturates, vitamin-K-rich diet (leafy greens)
- Missed dose：Take the day's dose when remembered; do not double the next day; record and recheck INR on schedule
Frequently asked questions
- What is Warfarin & INR Management?
- Warfarin reference: target INR by indication, high-INR and bleeding management per ACCP/CHEST, interactions and missed-dose advice. Browser-side.
- How is Warfarin & INR Management calculated? What is the core formula?
- Target INR 2.0–3.0 for most indications; 2.5–3.5 for mitral mechanical valves/high-risk. INR > 10 without bleeding: hold + oral vitamin K 2.5–5 mg.
- When is Warfarin & INR Management used?
- Bedside reminder of INR targets and how to manage a supratherapeutic INR or bleeding. Specific vitamin K/PCC doses follow institutional protocol.
- What are the key clinical points for Warfarin & INR Management?
- Serious bleeding: stop, IV vitamin K + 4-factor PCC (or FFP), haematology consult. Many antibiotics, amiodarone and azoles raise INR; rifampin and enzyme inducers lower it. Missed dose: take that day's dose when remembered; do not double up. Monitor every 4 weeks once stable; recheck 1–2 weeks after dose changes.
- What are the limits and cautions when using Warfarin & INR Management?
- For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
- How is Warfarin & INR Management calculated in practice? Can you show a worked example?
- Inputs: View Target INR → Result: Key point Target INR（Most indications: 2.0–3.0 (AF, VTE, first 3 months after a bioprosthesis, low-risk aortic mechanical valve), Mitral mechanical valve / high-risk: 2.5–3.5, Monitoring: Every 4 weeks once stable; recheck 1–2 weeks after a dose change） Inputs: View Interactions & missed dose → Result: Key point Interactions & missed dose（Raise INR: Amiodarone, metronidazole, trimethoprim-sulfamethoxazole, azoles, many antibiotics, acute alcohol/liver disease, low vitamin K intake, Lower INR: Rifampin, carbamazepine, phenytoin, barbiturates, vitamin-K-rich diet (leafy greens), Missed dose: Take the day's dose when remembered; do not double the next day; record and recheck INR on schedule）