International Normalised Ratio – INR
| Category | Haematology |
|---|---|
| Test background |
INR is derived from the PT; it is used to monitor warfarin dosage and will only be reported where a patient is taking warfarin or other dicoumarol drug. |
| Clinical Indications |
For the monitoring of vitamin K antagonist therapy (warfarin, phenindione, etc.) |
| Reference range | Therapeutic range dependent on clinical requirement for anticoagulation. |
| Sample & container required | 4.5 mL sodium citrate (pale blue top) adults1.8 mL sodium citrate (pale blue top) paediatrics |
| Turnaround time | 4 hours |
| Notes | Special handling: avoid prolonged stasis during venepuncture. Sample must be received by lab within 4 hours of collection. Please note: samples will be rejected if underfilled or overfilled. |