My recommended warfarin target is 2.5 but since Christmas my readings have been 1.9 and then 3.0 ( today .) I am on 6mg daily. The nurse is

keeping me on that dose, as the software recommended, for the next fortnight, then I have another test. I've had PAF for nearly two years and the last episode was in September when I was kept in hospital overnight for an angiogram ( clear, thankfully.) I really try to follow the warfarin guidelines. Also, recently I had a cholesterol reading of 6.03, so that is being monitored. Does anyone have fluctuating warfarin readings and if so, how do you deal with them?

36 Replies

  • Hi Penny,

    Such fluctuations are not uncommon. My GP has told me (several times now!!) that virtually everything we eat can influence the effects of warfarin on INR measurements. I was on antibiotics for several weeks which severely depressed my INR (2.5 down to 1.2, 1.3 ;'ish) and it took 3-4 weeks to restabilise. Conversely, when I re-started my Glucosamine tablets for joint care, these contain Potassium (as I later found out!) and it went from 1.9 to 3.5 in a week. The key (as you are aware) is to maintain a CONSTANT diet so that whatever your intake and mix of foods is, it can be balanced by the appropriate warfarin dosage. The main thing you can do is NOT to worry, but put your trust in your nurse to manage the dosage. My dosage was kept constant through the INR range of 1.9 to 3.5, at 36 mg per week, almost identical to yours. Don't panic, it will settle down.

    regards, Mallet-head

  • Hi Mallet-head!!

    Many thanks indeed for your reassuring reply. I do feel confidence in the care given both at my GP surgery and the local hospital and will try not to worry, as I've only been on warfarin for a year and am still coming to terms with the whole thing.

    All the best to you,


  • Hi Penny

    At the conference in Birmingham last year we had an excellent speaker on INR testing, and how complex and inaccurate it is, he said the best we could really get was +/- 0.5 for accuracy, and said if he was on warfarin he would err on the side of caution and ideally would like to be in the 2.5 to 3.0 range. So 3.0 is certainly nothing to worry about, my last two tests were 1.8 and then 2.9 on Monday just gone with no change of dosage, I just seem to be an awkward one with warfarin.

    Of course the dosage is irrelevant, doesn't really matter if you take 12mg or 2mg what matters is the INR result and we are all really different. There are alternatives now if you can persuade your doctor to prescribe them, and if you do fluctuate widely then these are an option.

    Be well


  • Mine went 2.5 - 1.8 - 3.3 in a few weeks after giving up alcohol. Also, when I first started on Warfarin it went up and down quite a lot.

    IMO main thing if it's going up and down, is to not go too long without a test. A fortnight max I'd say, not sure whether that makes sense but longer and I'd be getting concerned which is bad in itself. You need to feel good about it and that it's being controlled properly.

    Once my INR was going up very quickly (1.8 to 3.3 in ten days or so) and the next appointment was put back to a month away, so I asked for a test sooner which they did and a good job too as it happens.

    Best wishes


  • Many thanks, Beancounter and Koll for the info- I really feel reassured and am so grateful for the support on this site! When I asked the nurse about the alternative drugs to warfarin, she said they were not yet an option at our surgery, probably owing to cost.

    By the way, I have recently gone on to yearly check-ups for the PAF at the hospital, was told to be aware that I will be on anti-coagulation for life and that more invasive procedures ( like ablation ) are waiting in the wings. The latter has been said by every doctor I have seen and though in one way that is reassuring, in another it says that deterioration is inevitable! So are there people out there who have had AF for many years who have NOT had to have an ablation?

  • Hi Penny

    I self monitor and manage mine. I test every week and like to keep INR 2.8 - 3.0.

    I have been permanent AF for years and my cardio never mentioned ablation. It was only after the AFA Patients day a couple of years ago that I asked for a referral to see EP. The EP told me that since I had been permanent AF for so long, the chances of success were very low and in my case the risks were fairly high, so I opted not to have ablation. I have since read that the success rate with cryo-ablation for those in permanent AF is higher than rf-ablation. So considering going to see EP again to discuss. It appears that the sooner an ablation is done, the better the outcome.

    As has been mentioned in many previous posts, make sure that you are seeing an EP and not just a cardiologist. My cardiologists words were " he was just a plumber". The EP is "the electrical engineer". Since AF is basically an electrical problem with the heart, then the EP is the man to see.

    Hope you get things sorted out soon. Best wishes.


  • Many thanks Walter, and I wish you all the best re the cryo-ablation. I am under the care of an EP, though have seen two of his colleagues on my last two visits to clinic.

  • I've had AF for many years and have had 2 ablations, but I haven't had to have them. Both were just a quality of life decision to enable me to get off drugs, which I (and I think EP's) consider worse than the op.


  • Hi Penny. I found I had AF at age 43 and am only now heading for ablation 1. I have not been on anticog drugs until today. I have been told ablation is inevitable. My progress has been from Flecainide as pill in pocket, becoming more frequent until Dec just passed when I started 100mg x 2/ day. I started having AF as a cycle racer, probably once a month. Then slowly, frequency increased. Took a while to come to terms with it given I have spent my life doing sport, training 3-5 times a week.

  • Thanks Sam, I felt exactly the same, as I have been sporty all my life and had a very active job. One month after retirement, PAF was triggered by an abdominal operation and severe infection, but like you I have come to terms with it. I have had hypertension for 15 years and was always told it was well-controlled; now I'm told that it is a contributory factor for AF, so I don't know how to reconcile the two - does anyone else? Best of luck, Sam.

  • Hi Penny,

    My INR can leap about a bit, but I can keep it in check using my home testing machine. Not a particularly cheap option but for peace of mind I find it priceless.

    I still go to the surgery for tests when told and if I ever did get a scare I would ring for advice.

    Being a bloke and living on my own, and lazy in the kitchen area, I find the diet thing difficult to maintain. Whatever happened to meals on wheels?

    Reading the reports from Ian about the speaker on INR testing etc, and my own experience with different readings when tested in surgery and samples being sent to lab, (as well as chat with my doc), I am quite happy to aim for the higher end reading.

    As has been said many times, better a bit of a fuss over maintaining your Warfarin level than the alternative.

    All the best,


  • Absolutely agree, Ray, and thanks for your comments, as to everyone who has taken the trouble to reply to my query.

  • I've had AF for nearly four years and no mention of an ablation yet. It's got worse, but not so much that they're looking at other options - I know that ablation is supposed to be best carried out early but that doesn't seem to be how a lot of surgeries look at it...

  • I agree with you and think a lot of this delay is down to cost. I just wish doctors would be totally honest with us!

  • If a 6mg daily dose has taken you from 1.9 to 3.0 in a relatively short period of time, then I wouldn't be happy waiting a fortnight for the next INR test.

  • The software actually gave a four-week return date and to stay on the same dose! However, the nurse said she wants to see me in two weeks, so I felt that was helpful in the circumstances.

  • Hi sorry to hear that, well first off I stop worrying if you can. I am toying with the idea of getting my own blood tester as I live quite a way from my doctors surgery and it is a pain keeping it stable. I too have a target of 2.5 and I take an average of 2.4 a day, mix of threes and twos, it's bound to fluctuate a bit and it is dependant on the life style of the person and their bodily make up, 6 seems high but it must have kept it in check in the past? . keep your eye on your diet , I used to eat a lot of greens and it went up and down like a yo yo. Also new drugs taken for other ailments like my gout sends it up and down too. Good luck

  • Thanks, 5 or 6 has kept it in check mostly. I am fond of greens and may have had more than I should recently. Also suffer from indigestion, so maybe the antacids have helped to cause the problem. I will check that with the pharmacist. Good luck to you too.

  • I was told not to take antacids for at least 2 hours after taking my other meds as will affect their absorption


  • Thanks for that Eillen.

  • Hi Penny

    I was told the more boring your diet is as in keep eating the same things on a regular basis and stay away from alcahol it will help to keep your INR stable. This has certainly worked for me. Of course if you are on other medication this will affect it

  • Thanks Aprilryan, I've really cut back on alcohol and have two days each week free of it. Am on three other medications, though medical staff have them on my records, so I guess they are taken into account. Am glad you have sussed out what keeps you stable, and hope to do the same.

  • G' day Penny,

    This has happened to me very occasionally and my daily dose was around 5 mg or 6 mg. How do I deal with it - stay on the prescribed dose and it will adjust itself. My advice has been not to worry unless it goes below 1.5 and stays there or if it goes above 5.0 and stays there or gets higher. Also just watch your food intake and make sure you are following the guidelines.


    Aussie John

  • I've been on warfarin for nearly 7yrs now and I have not once had the same level, I eat the same don't drink alchohol, but never had the readings level I am on between 10 - 11 mgs a day I think it's just the individual no two bodies operate the same way! And mine certainly hasn't !

  • Thanks, MissL - am sure you are right.

  • hi

    12 years of warfarin and very rarely have i had a constant reading. My own thoughts are to keep it on the higher side (ie 2.5 - 3 for AF). Another pointer to these numbers is that as I understand it now, the recommendation for Dentists is it is OK to extract teeth with an individual on Warfarin of over 4.00. Time of day, and how long since last warfarin intake may all affect the result, and especially things like antibiotics or other supplements. Just read info before doing anything, which should be done by everyone anyway.

    On a lighter note, at my local Health Centre when I get my INR taken in Portugal, there is an official Portuguese NHS poster that includes the statement of `Drink a glass of red wine every day`, and that is just outside of the room where INRs are done.

  • Yes, a sense of humour keeps it all in proportion! Many thanks for the advice!

  • INR is a dark art for sure. Mine has been going up and down for the past 21 years My highest has been 5.6 but got that sorted quite quickly. I have had times were I have had to go to different hospitals in different catchments and they both have a different reading of 0.2 to each other.

    My Cholesterol was 3.5 before statins and is still 3.5 after I have been taking them for 13 years? Nobody has ever told me why I am on them? Maybe my age?

  • Offcut, I was thinking that, why on statins if your cholesterol is low? My GP wants me on them because my chol is about 5-6 without statins, but I won't take them as I get muscle spasms. Only tried Simvastatin though, might try another one if my c has gone up again.

    I'll stay off them if I can, don't like them. My brother had all sorts of problems with statins.


  • My sister has Lupus and she took them and had nightmares and when she changed them it stopped. They are strange things it seems

  • I got golfers elbow, tennis elbow and neck cramps. All gone now.

  • They go though the liver maybe that's why they can upset you?

  • Hi Penny 08. I've had parox AF for about 18 years, although it was only diagnosed 8 years ago. My Cardio was talking about ablations about 4 years ago but since I've been on Flecainide 150mgs x 2 per day my PAF has all but disappeared - 3 short episodes in 2 and a half years just before going to bed. 2 lasted 30 minutes before I fell asleep, the other 2 hours before I fell asleep.

    I have cut from my diet what I believe to be triggers so in the last 6 years I have drunk no coffee (definitely a trigger in my case) and little caffeine (4 cups of tea in 6 years and the odd can of Coke. Caffeine may be a trigger). I've also not eaten Soya, except as a minor incidental ingredient in some foods. I know that while Soya products, eg soya milk and yoghurt, tofu and miso trigger my AF.

  • Thanks Thomas, very interesting about the Flecainide. I'm on Sotalol ( was put on that in hospital after the PAF kicked off, and taken off Atenolol for hypertension.) I'm going to be on the alert for triggers from now on, so am grateful for your reply.

  • This is one of the main reasons I chose to take Pradaxa. I don't have these problems!

  • Thanks Warriors, the EP told me last year when he put me on warfarin that these alternatives will come in eventually, but my local surgery is not making them available yet and I hear that there is no antidote to them, which is a bit worrying!? Good luck to you though.

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