International Normalised Ratio – INR
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.
For the monitoring of vitamin K antagonist therapy (warfarin, phenindione, etc.)
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|
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.