Could you give your experience re range of INR and self testing/ management please?

Could I ask you about range of INR please? I have had lab test on two days ( when in A and E ) recently and both results have been 0.2 lower than than both my, and the warfarin clinic's. results on same day.

Last week my result was 2.0 so when I e mailed in to the clinic nurse I suggested that I keep to 4mg daily instead of one day 3mg, explaining I didn't want to drop out of range. She refused but I stuck to 4mg anyway and a week later INR is still 2.0. This means only 1.8 on lab test and my range, whilst 2-3 ideally should be 2.5

I am supposed to sign a contract saying I will keep to clinics instructions( just started self testing) but twice now I have had a better idea than the clinic and results have shown this. If anyone adjusts their own dosage, I wonder how you get this arranged!

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  • The nurses at the clinic have to stick to guidelines on a computer program or in a file.As you get used to warfarin you will have a good idea of how sensitive your body is both to warfarin or to vitimin k. If my reading is on the low side I try to eat a little less vitimin k before I would think of altering my warfarin dose. If I ever do alter the dose it is only by .5 a week to start with. Even that small amount can make a difference. Recently my reading was high for about a week and I had to visit the clinic to have my dose reduced. I suspect it will now be too low. We shall see!my experience is that the nurse will not alter it again unless I have a few low readings. That may seem ok to her but not to me who is scared stiff of having a stroke so I will probably alter it a little myself. If I alter it a little I don't notify the nurse as the chances are I will be altering it down again before long. As you are right at the start of your warfarin journey I would stick to what they tell you until you know how your body reacts to more or less warfarin. For example my readings seem to be affected quite quickly but my friend seems to have a 2 day delay before any alterations are noticed in the readings.I hope you can make some sense of this I seem to have rambled a bit. I suppose the bottom line is to be very cautious but at the end of the day you are self testing to be more in control. Hope this helps. It is only my opinion as a patient not a medical person.

  • Thank you Dedeottie, This is very useful and fits in with what I have found over the last few weeks.

    On the first occasion I thought the small change was needed there were no Clinic nurses in so i got one of the GPs to change it and I was on track a week later when tested- the same has happened this week so I will proceed cautiously and not mention the changes I make!! Thank you again,


  • Rosy, I do not self-test but I plan to start. Reason is that I went to the Patients Day and the GP said that it was his opinion that self-testing was better because there were fewer variables. As Beancounter said, the accuracy is only about 0.5 and that aiming for 2.5-3.0 was more desirable, and if you're self-testing, you could aim for that higher figure (if that's what you want to do) without having your dose altered all the time.

    Please someone correct me if you think I have got that wrong, but that is what I heard and I asked him direct at the round tables afterwards.

    Before going to self-testing though, I'm going to ask my EP about going onto one of the alternatives to Warfarin because the GP said that he thought they were a better bet and no testing required. But again, hope I've got that right? But if my EP suggest I stay on Warfarin, then I'll ask him about self-testing and take it from there.

  • Warfarin has an antidote were the others at the moment only have a half life. So if you had an accident and you were bleeding (not good) they could counter the warfarin and treat you without the risk of leaks from thinner blood.

  • mmmmm...being a farmer may not be a good idea to change from Warfarin then, I shall ask. Cheers Offcut

  • Hi Rosy,

    I've been self-testing for around 8 years now. I first started after having a couple of stays in hospital when my INR was up around 11. The second time I was working away from home and had arranged to go to the local hospital, where I was working, to have my INR checked since it was due. They said I would need to go in to have it attended to BUT they did nothing and sent me away at 11:30 at night. That decided me that it was time to do my own testing. After the local anticoag service falling out with me for adjusting the dose myself I am now "self-managing" as well. I check weekly and adjust the dose accordingly. I try to keep my INR around 2.8. At present my reading tends to drift up during the week. I am normally on 5mg but now need a couple of days at 4mg during the week to keep it at 2.8.

    Self testing and managing was the best thing I ever did since starting warfarin about 13 years ago. It gives me more freedom to get on with life without spending hours at the antocaog clinic like I used to especially since I am still working. I only have one visit to Heamatology each year so they can look at my record book to see that I have been staying in range.

    Hope this helps.

  • thank you very much- really helpful!

  • Your post is really interesting. I must admit to feeling like I'm treading a delicate line between keeping my readings at acceptable levels for me and keeping the clinic on my side. The nurse has no idea that I adjust my meds or they would say I had broken my contract with them.what do you do to become self managing . This sounds a good idea.

  • I suppose I went on to self management by default after the head anticoag nurse fell out with me. As part of the NHS reshuffle and centralisation of services I come under this nurse who was very much "you'll do it my way or not at all", so, adopting the AFA quote, "it's my body, it's my life", I did it my way, not hers, and just got on with it. She did email the haematology consultant, as did I and got no reply. She also contacted my GP and I just explained to her what happened. GP seems quite happy for me to continue and still provides the 'scripts for the warfarin. Having had several TIA's, (only 1 diagnosed), I am not going to let my INR go too low and to minimise the risk of a cerebral haemorrhage I'm not going to let it get too high. I also explained to them that I have spent most of my working life servicing and calibrating laboratory equipment so I am quite used to fine adjustments to get things "within range"

    The anticoag nurse did inform me that they have a legal responsibility to ensure that my INR is within range, but I suppose they have passed that responsibility on to my GP. So I suppose it will very much depend on the reaction of your GP as well, as to whether he/she is following current guidelines of getting anticoag patients on to self management where possible. I also accept that not everyone is a candidate for self management and would not recommend that everyone should be doing it. The main thing is that it works for me and if you feel confident to do it then discuss it with those responsible for your anticoag management.

    Will be pleased to hear how you get on.


  • this is very helpful Our nurse is just as you describe which leads one to self manage need to ask GP if I can do it but haven't sent the contract back yet but am self testing!

  • I am now testing at home but new to it. I was in France and went to 4.3 so halved my dose for two days and back on track. I did tell the nurse and he was fine about it - said if it happened again take nothing for two days. I now tweak it from time to time I.e. if it is 3.1 or 3.2 I take 5 mg instead of 6 or I eat a good plate of spinach although my nurse said this wouldn't have much effect unless I ate a lot over a few days. Anyway, I like having the option and if nurse is uppity about it don't tell them.

    Good luck


  • Sounds like a sensible plan to me.x

  • I have been on warfarin for about 4 years. I have a Coaguchek and have been self dosing for the last 2 or 3 years. I'm pretty steady - I take Vit K2 which helps stabilise my warfarin. My usual dose is 7.5 mg, but I have had to adjust that to 8 mg, then a few months later switch back, and even go down to 7 mg when it was at 3.0.

    I never told the clinic I self dose, I just did it as I found them too slow to react.

    Warfarin gives at least as good results as the new anti-coags as long as you remain in range at least 70% of the time. If you can achieve better than that (e.g. 90%+) then arguably warfarin is better. If you can't achieve that amount of time in range then you're better off on one of the new ones.

  • G'day rosyG,

    I 'self test' but do not 'self manage'. I have two sets of experiences, when I lived in Surrey my local practice was fully equipped with the handheld self testing device by Roche - Coaguchek XS. Brilliant and gave me so much freedom in my life. Also gave instant results. Since I've been living permanently in Cornwall my local practice uses the 'old fashioned' method of blood letting from the arm and sending it away to a lab for analysis and waiting 24 hours for results. Never had a problem with Coaguchek. In less than 12 months in Cornwall I have had 2 tests which were out of range (my range is also 2.0 to 3.0 with the ideal of 2.5) and the results came back without any adjustment to the doses. The first time I complained to my GP face to face. After the second event I complained formally in writing about the lab system.

    Comparing the two different processes (Coaguchek v Lab) the average the difference between the two processes is + or - 0.1. For my money the Coaguchek method is more reliable and accurate. Am off to Australia tomorrow and part of my luggage will be my device. If my readings 'chuck a wobbly' when I'm there I can at least take my device to a GP/Clinic or Hospital for assessment.

    I will not self manage - although I could - I believe in putting accountability and responsibility where it belongs - back with the experts.

    If you are new to Warfarin I would advise against 'self managing' until you have a good deal of experience with your food/diet and Warfarin.


    Aussie John

  • thank you John- good to hear 0.1 and also your experience- I agree re not self managing completely but will make the small adjustments people mention as find this keeps me in range,

    have a great trip!!

  • I bought a coaguchek machine a few months ago and check my INR weekly, although still attend my surgery when instructed, usually every six weeks. They know I have the kit and but don't know I adjust my dose to keep in range if it creeps too high, i.e. over 3,

    so I suppose I must seem in range regularly. My surgery has only recently started with their own coagchek and if I test straight after with my own it's there or there abouts the same. The one thing I noticed is that recently, because I was having other blood tests taken, they included an INR to the lab, and I tested mine on returning home. The difference was considerable, mine 3.1 result from lab 2.6. I mentioned this to the nurse the next time I went but she said transit times or temp sometimes effect blood samples sent for testing, and then of course there's the time waiting for it to be picked up. That's a bit worrying in general never mind INR results. Anyway I prefer to keep an eye on things myself wherever possible, and as I said to my GP if I got worried about a reading I'd contact someone.

  • kernow, Can I ask which one did you bought? Looking at the web there loads of Coaguchek's ranging hugely in price, £450-1300.

  • Thank you for this- I wonder if that's why we have 15 secs when using our machines and also whether it explains the situation someone wrote about here saying they were always in range and the cardioversion was cancelled as out of range on the day- significant for us if we are going in for procedures

  • Well you could always take your hand held with you and show them the memory record, or buy the additional attachment and keep the record on your computer, print off or send by email. Of course you need them to accept that your competence is equal to there's when using this stuff. Not all areas accept the self diagnoses route...see Aussie Johns post.

  • Hi there,

    I bought a CoaguChek XS from Roche Diagnostics,, all told with all the bits about £350.00. Apparently some health districts will supply the testing strips, they work out about £2.00 each, on prescription...... mine of course does not, but I have found it easy to use once set up and the back up seems very good.

  • Koll, I paid the same as Kernw43 recently and they even talked me through the first procedure!! Really pleased to be able to check myself as nurse in clinic wanted to lengthen times between checks and I have only just got stable INR

  • I just had a look at the CoaguChek website and they talk about - " atrial fibrillation and some other diseases with potential risk of blood clot formation require long-term, sometimes even life-long, intake of specific drugs ("blood thinners"), called coumarin derivatives or Vitamin K antagonists. They are used to "thin" the blood, in order to reduce the odds of complications such as stroke or pulmonary embolism." My understanding is that coumarin derivatives are NOT blood thinners but anticoagulants. This and the fact that the CoaguChek website does not appear to be upto date ( many data modifications are several years old ) makes me slightly worried that they are more concerned about marketing their products than factual accuracy.

    Personally I prefer to visit the nurse at my surgery as necessary for an INR check as I am not convinced the "home testing" methods are as spot on as one may imagine.

  • Beano 2013. I went to see my G.P. and he agreed that if I bought the actual monitor (Roche) then the practice would supply anything else. I have now used it for 6 months and have a fairly regular 2.5 INR. As you say after a few weeks of taking your INR on a weekly basis you soon learn what sends it up and down. (For example, spinach sends my INR up and I can reduce my tablets accordingly. ) Prior to having this facility I was going to the clinic every fortnight because my INR was so unstable. So for me paying £299 for this machine has been worth every penny. Best of luck.

  • Beano, Isn't spinach is very high in Vt K which would stop the warfarin from working so well and reduce your INR- maybe that co-incides with some other change in diet?

  • Re self-testing and management, one question is, what is a reasonable intake of Warfarin?

    I'm already on 7.5-9.0 mg per day, and even at that they are finding it difficult to get me over 2. I have touched 2.5 sometimes, often drop back, but never up. So why haven't they increased my dosage? Is there some sort of max figure?

  • Don't think there is a max figure but don't know for sure. I am on 11mg a day to keep between 2 and 3 .I was told that genetics ,exercise and how quickly your liver processes the warfarin all have a bearing on what dose you need. IF your reading is even as low as 2 they will say it's ok as its officially within your range and so won't increase dose. We A.F. ers of course would like it a little higher than 2! Good luck.

  • Thanks dedeottie. Been wondering why they don't increase my dose further and that's no doubt the answer, i.e. that if I'm generally over 2 they won't increase it. But I want to target higher so will speak to my EP shortly.

  • PS. Just had my latest results back, after having missed a complete daily dose, and I've jumped up to 2.5 !!!!!!!! No change in diet or anything else.

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