Low INR despite increasing warfarin dose?

[Sophia]

Hi All,

Happy New Year! I hope 2021 is better than the last one and everyone stays healthy and safe.

My INR has been stable at 1.8 (recommended range 3.5-4.0) for the past 5 days despite increasing my warfarin dose and not having changed anything in my lifestyle or diet. I have tested two different batches of strips on my CoaguChek machine and i do have symptoms such as lightheadedness, fatigue and cognitive slowing-down so I so I don’t think it has got anything to do with that.

Nevertheless, I will ask my anticoagulation team to have my machine calibrated with a venous sample at the hospital next week when i am due to self-test but I was wondering whether anyone has experienced this before.

Any input will be hugely appreciated!

Thanks so much! Take good care of yourselves!

Sxx

[KellyInTexas Administrator]

Do you have a bridging plan, and do you have heparin at home?

[HollyHeski Administrator]

Your INR is far too low, as Kelly says 'do you have any heperin/ bridging plan?As you are having symptoms, I would presume your machine is reading correct, so I would recommend talking to your team sooner rather than later?

I'm not on warfarin so I can't suggest anything other than heperin.

[Lure2]

Hi Sophia,

I can not understand why it has become so exstremely low as 1.8? Had you done an operation or what has happened?

You selftest and I know you have had problems with batches earlier like most of us had when Roche had some trouble with the CoaguChek XS but those days I thought was over now.

My hospital here in Sweden has changed to another metre and do not have the CoaguChek XS any more so I can not follow that one.

It is much more difficult to get back to the correct level of INR is it is too low. It can take some days.

You should have some Heparinshots or Fragminshots to take when it is under your therapeutic INR of 3.5 - 4.0. Otherwise you can have a clot or something. Do not make too many changes of the Warfarin before you know where it " lands" finally. Do not eat so much greens now when the INR is low. Make notes of everything you do with the machine and the Warfarin and the greens etc.

Only the veinvalue is the correct one. Usually with the CoaguChek XS the vein-value is higher than the fingerprickvalue. How much you have to find out yourself by parallelltesting within a couple of hours. I guess you already know these things.

[Lure2 in reply to Lure2]

Wrong again.... the fingerprickvalue is usually HIGHER than the veinvalue. So difficult to get it wright. Sorry!

[MrsMouseSJ]

Hi Sophia. I was asking a question along these lines very recently. In my own case, I knew what had caused my INR to drop: I had to up my daily dose of PPIs which, after a few days, made my INR too high. I then withheld a warfarin dose for a night, then reduced it - as per medical instructions - and my INR fell too low. Despite then increasing my warfarin again, and 'front loading' i.e. a couple of high doses to start with, my INR fell further. I was left at the mercy of all manner of unpleasant symptoms.

It has taken around a week for me to get it back into range. It has been years since my INR was this low and, with the dizziness gone and having ventured into the loft and found some very old warfarin record booklets, I see that the last time it dropped low - due to my having internal investigations and needing a low INR - it also took quite a while to get it back into range. Or what certainly felt like quite some time!

So, I wouldn't worry too much - although, with your INR being below 2, you should be speaking to your doctor asap about heparin injections (if you haven't already done so).

In terms of your Coaguchek machine, I have just had mine double checked against the machine at my doctors' surgery - and they gave the same results. Like you, I had worried about whether it might be an issue with the new batch of strips I have. But it wasn't.

Good wishes.

[Sophia]

Thank you for all you responses! INR was 2.2 this morning so i shall email the anticoagulation clinic tomorrow and ask them for an appointment for a venous sample. If that is the same, i will contact my doctor. It is very strange as i have changed nothing in my diet or lifestyle. It is a bit like the warfarin doesn’t seem to work. I am sure the strips are working fine not like the fiasco a couple of years ago. Will keep you informed of what happens. Thanks so much for your support! Stay safe xxx