INR sure this a blip!!!? Advice please!

Been on same dose (5mg a day + 1mg on one day a week) since 02/14. INR's been very stable and only been higher than 3, twice in all that time.....both times computer wanted to drop dose, which I ignored (as when previously on 5mg for 7 days, INR went BELOW 2). Last 10 INR's have been between 2.4 and 2.7.

Despite me telling the nurse, some months ago, that I was still taking the old dose, she never bothered to override the computer and correct it, so computer thinks I am on 5mg a day for 7 days.

Today my INR was 3.6 and of course, again the computer wants to cut the dose - this time to 4mg tonight and again on Tuesday. I am very reluctant to do this, because I feel my high INR today is merely due to "Christmas diet" and my not having had my daily handful of salad leaves with lunch + 2 green veg in the evening for over a week.

I confess to be very (and possibly over) anxious about INR's dropping to below 2, as i had a blood clot some years ago, before I had started on Warfarin.

How high is 3.6?? Anyone else had a blip like this?? Think I would rather 'veg out' than drop my dose!!

There is no reply from the any volunteers about please, or fellow AF'ers on Warfarin???

46 Replies

  • Mine has been 3.9 for two weeks running now, Christmas diet as you say, not enough green veggies! The nurse said not to worry though... I'm just eating sprouts like crazy. I've got to drop my dose too, but am just arranging to buy a CoaguChek, did you know you can get them half price through Roche, with a two-year interest free payment period? I had no idea. Done like that it's do-able. The surgery will let me phone in my readings and will give me the test strips. Very happy about that!

  • They won't entertain self testing on the Isle of Wight unfortunately!

  • I was gobsmacked that ours would - I'd only expected to use it to check myself in between surgery visits, but they've been incredibly helpful. Colour me, well, tickled pink! Sorry they won't go for it on the Isle of Wight, that's a real shame...

  • Can you please let me have the link to the Roche offer.


  • You just call them on 0808 100 7666 Jean :)

  • Thank you will give them a call in the morning, as guess they are shut now. Is it the CoaguCheck XS that's the one to get?

  • Yes, I think that's it!

  • Have just called Roche re cost of CoaguChek and they're not on offer and never have been. Cost is £299. Did you perhaps have a voucher or discount code?

  • Hi Jean,

    I thought that was about half price, I've seen them at double that before on Amazon and didn't realise you could get them for that... Perhaps it's only a surprise to me! The interest free payment thing is really helpful. Sorry if I misled you with my enthusiasm!

  • Not to worry, think I may still buy one. My GP said quite cheerfully this morning that they would supply the strips etc. Are you thinking of getting one?

  • I am in the process... You fill in a form and send it back to them, and I am going to post it tomorrow. Good news that your GP will supply the strips!

  • Do you have to fill in the form before they'll send you the CoaguChek machine and do they post the form to you or do you print it off yourself?

  • Yes, though I think it could just be to do with the payment thingie... They send it and you send it back, terribly old fashioned :)

  • Thanks

  • 3.6 is not a worry I would say. Some years ago at HRC we had a talk from a bloke who was the top expert in INR testing in UK and he told us anything up to 5 was generally safe. I have a similar problem with my nurse/computer and tend to do my own thing although I obviously can't advise this .


  • Thnaks Bob, I think we must all become advocates of our own conditions, don't you?

    Right, wheel in that barrow load of sprouts!!! : )

  • I'm on warfarin also and have had a bit of a struggle to stay in range due to eating a high veg diet. I self test and send in readings to clinic.

    I certainly wouldn't let myself get to an INR of way , in spite of what anyone said. With 3.6 I would max our on the green vegetables to get back in range.

    I highly recommend the coaguchek testing apparatus. I'm testing every 2 days at the moment. and it's so reassuring to be able to do so. I make small adjustments myself.


  • I suppose there is no reason why i shouldn't buy a Coag check and use it keep a check on my results in between visits to nurse........even if the surgery doesn't like the idea.......???

    Might get more discount when buying one, as i work for the NHS (fat chance!)

  • Your surgery is so behind the times, but then I do hear the IoW is more like the 50's!!

    I'd get a Coaguchek anyway, would they at least supply the test strips?

    Healthcare is all about patient involvement now rather than the old patronising way. There's no way a medic could keep me as well within range as I do through self-testing and self-dosing.

  • Exactly - good post Mark. I agree entirely.

  • Sorry...been away for 3 days.....hence no response from me!

    Yes we do lag behind in many things here!!!

    I was refused when I asked last time, as they were only just piloting self testing at another practice. I will chase up in the you know how much the Coag strips cost, Mark?

  • Coaguchek test strips are about £68 for 24....price could be a bit higher but not much lower


  • No reason at all Wightbaby. When I moved to Cornwall and moved to the surgery who wouldn't support Coaguchek ( refer my post to you earlier about my experience) I did exactly that. I used the Coaguchek to monitor the INR clinic venous draw technique. Now the thing to bear in mind is that the two results, one from venous draw and one from Coaguchek will never be the same, there will always be a variation (if they do happen to be the same that's all it is - happenstance !). The two testing techniques are both stand alone techniques producing stand alone results. I have to say though that using the Coaguchek I twice was able to challenge the results of the venous draw and the dose of warfarin that emerged from those tests. I forced the GP to go away and review. And twice I got an apology for mis- dosing !!!

    If I can find my file I'll dig out the reference to the two techniques and post the reference on here for those who are interested.


  • This is very interesting and I am not stupid...but this is a bit technical for me!!

    Is the venous draw, a finger prick? If so how does Coagcheck differ?

  • Hi Wightbaby,

    Venous draw is the normal sort of blood letting, needle in vein in the arm, inside arm around the joint fold, draws blood out, bottles it, sends it away to a labroratory where it is tested and the results sent back to your GP, along with details of your next test and warfarin dose. It involves attending GP surgery or INR Clinic every time a test is done.

    Coaguchek is almost identical to a diabetics blood test - just a finger prick, drop some blood onto a test strip which is in the device and bingo an instant result. Phone that result to your supporting GP or INR clinic, they feed it into their computer and the appropriate programme tells them the new dose and new test date. They then phone you back and tell you what to do next. simpler and faster and great for those with a busy lifestyle and / or who are still working or who have difficulty in getting to a GP or Clinic. Its highly portable and can be taken anywhere at any time. Gives you total freedom Its the actual testing equipment that is different Coaguchek is a portable handheld device with its miniature testing/ analytical device built into it and the venous draw requires different equipment laboratory based to do the job. Blood also can change once drawnfrom the body and the time it takes to be tested can contribute to a different result from Coaguchek which is virtually instant.

    The Coaguchek device tests run by me in parallel to the laboratory test has twice proved mistakes were made in the laboratory. With Warfarin - two mistakes is two too many !


  • I have the Coagcheck type test...never had or been offered the venous one!

  • My target has always been between 2 & 3 and I tend to feel slightly, probably unnecessarily, concerned if it approaches 2 or 3. I have to have my tests done at the doctor's surgery - no self prescribed allowed. .

    See how the increase in greens affects it.

    Also alcohol affects the effectiveness of Warfarin did you have any over Christmas?

    Keep monitoring.


  • Ahem!! Good point!

    Well I usually have none but confess to a small glass (red wine) on Xmas day and a couple of similar size of Mulled Wines in between times.....could that affect INR's that much? Maybe combined with the 'lack of greens', it quite possibly could?

    Never touched any cranberry by the way.

  • The important thing is consistency.

    For me, because I have had a number of ablations and cardioversions I decided to keep strictly to a regular diet and also to sadly cut out the alcohol. The purpose being to minimise the risk and as much as possible give the doctors the best chance of success in defeating this accursed AF.

    For cardioversion they prefer my INR to be between 2 & 3. This was also the case when I have had my ablations.

    Hope this helps.


  • Thanks Pete.

    Yes, I am usually very consistent and strict with my diet, which is why I imagine my INR usually pretty stable, but of course, over Christmas "I strayed from the path"........!!

    My consultant and EP suggested that for myself, both cardioversion or an ablation, have only 50% chance of success..... I have been in PAF. for well over a year now.

    Quite reassuring to read your lower post re Vit K injection though.


  • I was being monitored by a Specialists registrar at a Public Hospital ( Au ) and was told that due to being in AF for so long , 31 months at that stage,

    ( and that was my fourth time I had been in AF over the years )

    that I had little chance of having success with another cardioversion .

    So I got a referral to a private Specialist who ran all the tests and arranged another cardioversion . Even he was surprised when two months later I was still in sinus rhythm without having / taking any beta blockers .

    Five months now with no AF episodes and the need for an ablation has disappeared.

    Just needed a Cardio specialist who wanted to see what would happen "if" - a change of drugs and cardioversion.

  • My INR last Friday was 4.2. Like you I generally stay on the same dose of warfarin, so goodness knows why it jumped so high within a week of my last test. I came home and looked up online what contained a lot of vitamin K and as I had a pot of parsley on the window ledge I ate some of that. I go back for another test tomorrow and will be paranoid if it's gone below 2. My heart has been playing up constantly since Christmas day evening and there'll be no chance of a cardioversion if it is below 2.

    Like you I hadn't eaten any salad or greens for a while.

    A few years ago my INR went up to 6.something. My surgery didn't appear to be shocked by this.

    Honestly,you can't win can you!

    I'm going to look up the CoaguCheck.


  • Jean, It sounds like a few of us have had "a dose of Christmas!!!"

    I thought Vit K STOPS Warfarin working and makes INR drop - that is right isn't it?

    6 eh?...well you are still here to tell the tale!! Good Luck with the cardio'...let us know how it goes.

    I am off now to eat some sprouts with dinner and some baby green leaves!!

  • Yes - vitamin K reverses the effects of Warfarin.

    I was given a vitamin K injection when I severed my artery in my hand last January to stem the flow of blood. All a bit dramatic but I am still here to tell the tale.


  • I have taken 4.5 mg this evening. I think it only needs a small tweak to get back on track.

  • 3.6 is nothing! A relative has a mechanical valve and they aim to keep him between 3 and 4. It is usually a higher figure for mechanical heart valves than for AF. I usually rejoice to get such a good figure.

    Then there is the natural variability to consider. Almost no research has been done on that. From 23 years of self-dosing, therefore able to follow my own rules, I can confirm that for one person, me, it is as high as 2.5. That means, anything from 2.5 to 5.0 is nothing to bother about. Most of the time, the body auto-corrects, if you let it. Statisticians call it 'regression towards the mean'. Biologists call it 'homeostasis'. If you fight nature, then you often end up making things worse. I can document this. Simply put, if you change the dosage when you do not need to then you are likely to create swings, with even greater extreme values.

    My favourite easy to read Research article on this is: Kim YK et al.2010. Effect of a simple two-step warfarin dosing algorithm on anticoagulant control as measured by time in therapeutic range: a pilot study. Journal of thrombosis and haemostasis vol 8 p101-106. See Table 1 on page 103


    The usual procedure with one out of range figure is to wait 7-14 days then retest. It takes two undesirable results at least a week apart to merit a change. Then you consider a SMALL dose change of around 10%.

  • You are SO knowledgeable ILowe, but some of this is too technical for me, haemostatis and algorithms etc........this is all beyond my comprehension!!

    it will be interesting to see if that tiny change I made makes much difference. I have also tried to veg out on the green stuff over the past few days, despite staying in someone else house (AND eating out) ...always a problem with the diet!!!

  • This forum is a great place, because we are all interested in a common set of problems. It is sometimes difficult to know in posts, how technical to get, so I usually mix them both. I have spent my professional life, cutting through complex subjects and explaining them in a way that is understood, while being consistent with the more complicated. To reassure you, I frequently read stuff that I only partially understand, but that does not bother me. So, what I was saying from the paper:

    1. It takes two tests at least a week apart to merit a change in dose.

    2. When you change, make it a small change.

  • I tend to eat spinach three times a week as well as my usual greens. My theory being that as I then have a highish but K diet any changes with sprouts and salad are a small percentage of my total vit k in take. Did drop 0.5mg warfarin one day over Christmas as spinach got a bit lost in the festivities. I do not advise anyone else to juggle of course! Warfarin takes a while to play catch up either way so yes leave it a week and see if nothing else has changed,viruses,pain killers etc.

  • I tend to think this way regarding greens also!.......being away for 3 days over NY, and eating in someone elses house, hasn't really helped.......I found myself buying a bag of green leaves and noshing on those just to keep myself topped up!!

  • Yes. My daughter still has a very doubtful tin of spinach I took "just in case"

  • In 2006 I bought coagu check Xs online and Im buying the test strips .I have mechanic mitral valve.I m self check and i do my own Inr has to be 2.5 -3.5..I had few times my Inr below 2, one time 6..Im using different blood thinner its called sintrom, has shorter peak and stay for shorter period in the body..3.6 is nothing to worry..Dont eat too much vegetables hight with vitamin K bc it will take more time for blood thinner to work..

    Buy the coagu check and you can test how oft you want, so you will not be under stress and you will not destroy your veins.In 2 min you have the result and you will know what to do..

  • I had a blip a few weeks ago. Had been on 10 weekly tests, so no way to be sure how long inr had been around 3.3 when it had previously settled around 2.5 over the previous year. In hindsight, I had been out of my normal routine - off work, so no canteen lunches with daily salad or leaves at lunchtime and hadn't been eating much of anything else due to a slightly queasy tummy. Also have a bad habit of not drinking enough when I am occupied at something at home like knitting. Put back on weekly testing and warfarin slightly reduced from 5mg per day to 4.6mg (so some days 4, some 5) and after 4 weeks am back in range and back to monthly testing. Also back to my more normal diet.

  • This sounds a bit like me!! Not being at work and christmas have just messed up my diet routine!

    I try and get tested approx every 6-8 weeks. I think 10 weeks is too long in between, when you consider how quick the results can change in only 7 days!!

  • 10 weekly tests were set by the anticoag clinic, not me. Now up to monthly after a couple of good results. Am so grateful GP surgery does my finger prick INR tests. Waiting times at our hospital blood testing clinics have been dreadful, but the staff there are great, especially as my veins play hard to get.

  • Hi Wightbaby,

    Sounds pretty normal to me, sounds just like me. No worries !

    I can go months and months stuck in the range 2.4 to 2.7, on 70 day tests ..... then for no reason it drops to 1.8 or 1.9, and gets stuck in "low mode". INR clinic then plays around with the doses and WHAM ! up it goes back into range again.

    This happened just recently, For no reason it dropped to 1.9 and got stuck there .... my dose at the time was

    Mon Tues Wed Thur Fri Sat Sun

    5 5 6 5 6 5 6 = 38 per week

    so then she rearranged the doses as below

    5 6 6 5 6 5 6 = 39 per week

    So for me it was as subtle as that .... funny old stuff this warfarin. Baffled me at the time because me food and booze intake was fairly constant even over the Christmas period.

    As a matter of interest I have never gone any higher than 3.3, in fact my tendencies have always been to drop rather than go higher. As I say weird stuff this warfarin.

    When I was diagnosed with AF and put on Warfarin I lived in Dorking, Surrey and my GP's INR clinic solely had the Coaguchek self testing device and provided full support, including training and device monitoring. That's how I got onto it.

    I later moved to Cornwall and the GP I started with only did the venous draw. I found this unsatisfactory and interfered with my lifestyle too much I asked the local CCG to tell me why I couldn't have the Coaguchek device. No answer at all - bloody useless. So I rang around all the GP's in my area and found one who used Coaguchek. I asked if I could come aboard, I was interviewed by my GP, and taken on. So now I have this great GP and INR clinic, get the same deal as I had in Surrey, including the monitoring of my device - every 10 tests I have to take it into the clinic and we do a blood test on both their device and mine to ensure that the readings are the same. Sometimes they are and sometimes there is a variation of + or - 0.1.

    I know this isn't appropriate to you on IOW but just thought my experience would be interesting useless information for you and others. :-)


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