stupid or what

[Christinedbur]

I bet its really simple but what is INR? Bet I will feel really silly when you tell me?

[Rellim296]

It's all to do with Warfarin and you'd never guess - International Normalized Ratio. It's a recognised way to gauge the results of the prothrombin time test, which measures the time it takes for blood to clot. A normal person's blood will give an INR of 1, and if anticoagulated blood clots in twice as long as that, the INR is 2, with 3 for three times as long and so on. An INR between 2 and 3 is deemed to be just what the doctor ordered, over 3 is OK, over 5 is too high and higher than that is not good at all. A high INR can be reduced by ingesting vitamin K.

Is that any help at all? Please correct me anyone if any of it is not exactly right.

[mpaulb3633 in reply to Rellim296]

The prothrombin time (PT) — along with its derived measures of prothrombin ratio (PR) and international normalized ratio (INR) — are assays evaluating the extrinsic pathway of coagulation. This test is also called "ProTime INR" and "PT/INR".

[Rellim296 in reply to mpaulb3633]

I think ProTime INR and PT/INR give a far better indication of what it's about. International Normalized Ratio could mean almost anything!

[Beancounter Volunteer]

Rellim is right, but don't feel stupid, I would be willing to bet it's only known to those of us on anti coagulants, and probably a small part of the medical profession

Be well

Ian

[byoungccs]

Excellent technical explanation Rellim296.

In non valvular AF good to keep INR between 2 & 3 and if Clinic finds you are too high they may suggest reducing dose of warfarin which will reduce risk of bleeding if prolonged eg nose bleed etc

If INR too low, you may be advised to increase warfarin dose to reduce potential stroke risk which is why warfarin is used in people with AF.

INR readings are influenced by certain foods and drinks eg alcohol and before advising a warfarin dose change the clinic should check with you if you have changed your diet significantly before recommending dose change.

Warfarin is very protective against risk of stroke and important to have a stable INR and diet.

Other new Anticoagulants (NOACs) are available which work as well as well controlled warfarin, don't need INR monitoring, minimal side effects and less affected by what we eat and drink.

NOACs however have a much shorter effect and need to be taken once or twice a day as recommended or there will be no stroke protection.

Good luck and there are no Silly questions and I hope explanations help reassure you by knowing what you are taking.

[beardy_chris]

I think that, from some of your previous posts, you are on Rivaroxaban (which is a NOAC). If I'm right, you don't need to worry about your INR at all - it is only when you are on Warfarin that it is an issue.

I'm not quite certain why though the explanation I got was that NOACs work in a different way so the INR test doesn't work.

So, I guess, the test probably doesn't measure clotting time directly. I had a mental vision of the test involving seeing how far a drop of blood slides down a glass pane - but I guess it's a bit more scientific than that!

As the others have said, it's not something you need to worry about if you are on a NOAC.