My INR result is reducing

I have been taking Warfarin for 11 weeks following a Pulmonary Embolism. My INR once in range was stable ( therapeutic range of 2.5-3.5), but it is dropping 2.0, 1.9 and now 1.8. My Warfarin has been increased, but I am finding this result quite strange. I am feeling well and the only thing different in my routine is that I am increasing my exercise. Is this variability in INR result common when taking Warfarin, and should I be concerned?.

21 Replies

  • After such a short time on Warfarin it is always a good idea to keep the medics posted and share your concerns with them. However, in my experience you can expect your INR to move about a bit which is why despite having a target of 3.0 you are given a range of 2.5 to 3.5. Changes in diet and levels of activity as well as other medicines can all have a surprisingly large effect on INR and that is normal. If it happens a lot then the answer is to test your INR more frequently.

    In your case I would not be so worried about the change in INR to this extent! However, it seems that all your last 3 readings of INR are in fact out of range and too low suggesting that an increase in warfarin dosage might be called for. I would refer to whichever medic is managing your Warfarin level quite soon and challenge them to reassure you.

    All the best

  • Thank you for your reply especially when you have obviously been so ill yourself, I wish you a speedy recovery. My Warfarin has been increased, but until I experience the highs and lows of this drug I will probably be concerned. Warfarin does not appear to be very robust, as I take no other medication and have been told by the consultant (albeit the doctor who looked after me after my PE) to increase my exercise to improve my lung function. I didn't realise that increasing activity would have an effect upon INR.

  • I have atrial fib and have had two cardioversions and due another in one week. my inr has been stable at 2.7 but last one is 1.7

    I need 3 stable results for cardioversion.

    Are people aware that laxatives of any type can effect results?

    Visitors insisted on giving me magnesium as a good help for the heart ,but I didn't know it contain a laxative,i felt quite spacy and breathless and have probably lowered my inr .should I take more warfarin .?

    I am a vegetarian and usually eat lots of greens,but have cut down ,probably too much ,now I presume I am deficient in vit k,result lower than ideal inr result.

    Should I eat more of leafy greens ? I think because of the mag lax my inr will be decreased preventing me from having cardioversion next week.

    This my 3rd atrial fib episode,with eratic pulse, after cardioversion all back to normal,with 3 grams warferin one day 4 next.

    Due a blood test in two days ,is there a way I can have a prefererable result by diet or increase of warfarin.

    Re laxatives , no medical person advised me of laxative problem! I had to go through months of feeling spacy and unsteady before knowing about laxative use.

    I fell and broke my leg while spaced out.i had every test in the book to find out about why I was unbalanced and spacey.

    Only when I stopped taking laxatives of any sort did my equalibrium return ,then when I told dr and specialist they confirmed I shouldn't take laxatives.!I would have assumed they would have thought of this before all the tests

    My best advice came from checking online!

  • hi im on warfarin for life, range of 2.5. have found over the years many things effect the stability of it....... i have to be careful of other meds, too much green veg/salad, have also to be very wary of different toiletories/make up/shampo o etc, all have been noticed to alter my range so have to stick to tried and tested, keep away from products containing vitamins etc, drinking alcohol not a problem as long as its regular (not toooooo much tho), my inr nurse once told me we treat alcholics so as long as we know your drinking its fine.everyday products are my downfall, many a time have to sit and think what ive had or used thats different from normal, am young enough and been on it long enough to know the ins and outs of warfarin treatment but feel for those who dont understand it or have poor inr nurses.

  • Hi and thanks for your own personal experience. I didn't know it was going to be this complicated!!!.

  • It can take some months to really get stable and understand your warfarin dosing needs. Then someone goes and changes the clocks!

    Yes something as seemingly simple as that can change your body's metabolism and warfarin processing. Every spring and every autumn I need to watch my INR more carefully and adjust the dosage accordingly. Similarly when going abroad and changing time zones or living in hotter/colder climates.

    I live my life as I did before warfarin. I do not avoid alcohol or green vegetables, as the professional will have you do and I still have a stable INR. This is because I realised very early on that if my INR was going to be where it was supposed to be then I had to take charge of my testing and dosage. I bought an INR tester, a Coaguchek XS, my GP provides the test strips on prescription and I test weekly adjusting my warfarin as necessary.

    Six weekly testing proposed by the professionals at the path lab is far too infrequent in my experience and most doctors/nurses don't take warfarin so don't really know what they are managing. I also know now that a couple of glasses of wine will increase the INR so I reduce warfarin a little on that day to compensate and my INR stays near my target value. It's surprising just how often I am on or near my target INR.

    I have noted too that many cosmetics contain coumarin (= warfarin) because it smells sweet. It's worth reading the ingredients on these items. This can affect INR in my experience.

    Be patient and your INR will settle to a normal level for you. Everyone is different. Take control too by self testing and self management.

  • From my personal experience the one thing that regularly depresses my INR level is dieting, whereas rich foods seem to raise it. Bear in mind that changing your dosage may only show a result after about 48 hours (in my case). I always think of it as changing the course of a cruise ship, if you over steer by panic reactions you will probably have to correct later!

    As always I will be testing more regularly over the holiday period because of diet and alcohol consumption changes. You may find that you settle down and the only require minor tweaking, e.g. half a milligram difference from my standard dose in my case, to stay in range. Before I became self testing/managing my results were all over the place. I have never found a connection between increased exercise and dropping INR levels for me but that doesn't mean there couldn't be one.

    Best wishes

  • Hi there I have had a dvt and pe many years ago and found that the weather also has an effect. That is in the summer my INR goes up and in the winter and the cold it goes down and I need more warfarin.

    Exercise speeds up your metabolism and this increases the speed at which your body deals with drugs (warfarin). So more excercise can decrease your INR. However from talking to other people it does vary from person to person a lot.

    I certainly found that my levels took longer than 11 weeks to be truly stable and even then it wasn't for long because as soon as I had two readings in range they increased the time between visits from three weeks to 8 weeks and I went in and out of range every time.

  • Hi Gel1,

    You have already received some good advice from other members but I'm interested in researching why your INR dropped like it has. Correct me if I'm wrong but you said you "started your warfarin 11weeks ago and was stable on discharge.

    1. I am interested in why you were started with an INR of 2.5 to 3.5 as this is only normally give for a second PE while on warfarin?

    2. In the 11 weeks since your discharge, you have had 3 INR tests. It is normal INR therapy that you are tested every two weeks until your INR is stable, which don't appear to be happening in your case.

    3. Normal INR therapy for a first PE is 2 to 3 with a target range of 2.5. However, if your INR drops 0.2 below or above the 2 to 3, would be acceptable but your INR provider should increase your dosage, which again did not happen.

    I would strongly advise you to discuss your anticoagulation therapy with your provider at your next INR test. If you feel you have not been listen to, go and discuss your concerns with your GP and if necessary ask to see your haematologist at the hospital, raising the points 1 to 3.

    Please let us know how you get on as this helps other members to understand their warfarin therapy.

  • Hi Firemansam Sorry I didn't go into detail, but below is the scenario.

    1. I was given an INR range of 2.5-3.5 as it was my first event but bi-lateral.

    2.At discharge (from 1 week in hospital) I was 2.2, 1 week later 3.3, 1 week later 3.3, 2 weeks later 3.4, 3 weeks later 2.0, 1 week later 1.9 and this week 1.8. My Warfarin was increased when the value was 1.9 and again when at 1.8. I am confident that I have been recalled when my values were reducing and warfarin increased accordingly. My overall concern is why is this happening, and wanted to canvass other peoples opinions based on their greater experience. Their replies have been interesting, and very helpful, as have yours, I am learning more with every reply.

  • Hi Gel1

    Thank you for supplying your INR test results.

    Like you, I suffered a acute bilateral pulmonry embolism but was started on a therapeutic range of 2-3, which as I explained is the most common range for anyone who has had their first PE. I don't see why you need to take more anticoagulant then necessary and would discuss this with your anticoagulant provider to ensure you have been correctly assessed.

    You are presently achieving a Therapeutic Range of 50% and the gold standard is 60%, which means in my opinion you need weekly INR test until you achieve the gold standard. What most anticoagulant providers say, "If you have two consecutive INR reading within range, they will then do another test in 2 to 3 weeks. In my opinion this is too long unless you are fully stable. I would ask your anticoagulant provider to do weekly testing until you reach the gold standard of 60% in range. In my opinion this is still too low and they should be able to reach 65% + and people who self test can achieve 80% to 90%.

    Please let us know how you are progressing especially over the Christmas and New Year.

  • Thank you for this FIremansam, I feel more at ease that your range for the same acute PE was lower, do you think though that different consultants have different theories, on range and length of time you remain on Warfarin for a primary event. I will speak to my GP after Christmas about self testing but if I am only to remain on Warfarin for 6-12 months is it worth investing in a CoaguCheck (about which I knew nothing until I used this website and received the INRreview magazine).

  • Hi gel1

    Great to hear you are more at ease but please ask to be tested weekly until your INR is stable at 60% in range or better, which weekly will do if they monitor you regularly.

    Yes, different consultants do have their own theories but the range for first PE is 2 to 3, unless u are unlucky like me and had a second acute bilateral PE's. However, I did finish up in hospital because my INR was below my range, which means being subtherapeutic as my provider left me too long between tests, so don't let this happen to u. It is their duty to maintain your INR within your range.

    I agree there is no need to buy the test equipment if u are only on warfarin for 6 months but u need to be tested regularly and argue your case that u have been subtherapeutic 3 times out of 6 tests, which is not a very good start. As explained, first PE is normally 2 to 3 and u can go below or above by 0.2! So u do not want to go below 1.8 without advice from your anticoagulant provider.

    If you feel that weekly testing is too much of a waste of time and u feel safer testing yourself, then buy the monitor £200 but make sure your GP will provide the test strips. Then sell it on ebay as they go for a god price secondhand!

  • Thank you for advice FMS, bloods nicely back in range now. Thinking of holidays now but as I started to feel unwell the day after I returned from a short haul flight (my PE was blamed on this and other factors), I am naturally concerned about flying. Do you fly and if so what precautions do you take?

  • Yes, and am currently flying around Thailand and Malaysia for the next month with my wife and daughter. However, when I had my first PE's, I was told not to fly for 6 months and only take short haul after that. I am surprised that your consultant has allowed u to fly while u still have PE's but as u say, they seem to have different rules. Before my PE's I have flown to Australia 3 times but this time we are flying business class for the leg room and extra comfort. There is some data that say u are properly safer flying while on warfarin then most other flyers but more research is needed.

    I don't drink when flying (use to) and drink plenty of fluids. I always walk round the plane every hour and do the recommended leg exercises, might be over the top but better safe then sorry.

    I have already had food poisoning, which is playing havoc with my INR. Luckily, I have my monitor to keep me within range and presently testing every 3 days until it settles down.

    I am glad to hear your INR is being monitored as this is one of the most important, no, vital requirements when u are on warfarin.

    Please keep in touch how your INR is progressing.

  • Hi FMS

    I haven't flown since my PE (my first one ), and wont fly until after I see consultant at my 6 month check, but starting to think about holidays. Glad that you can still travel by air whilst on Warfarin. Hope you recover quickly from food poisoning and that you are having better weather than here. Happy New Year (you will see it before us).

  • Hi FMS

    Hope you have recovered from your food poisoning and that you are enjoying your holiday. I myself have had a lovely weekend away in London doing touristy things like the Cutty Sark (which was ace). My INR was 2.6 this week so am in range. Its snowing here, hope its better with you.

  • Don't forget, almost every other med reacts with warfarin, as do other factors, such as smoking, intake of vit k (found in green leafy veg etc), Grapefruit juice, cranberries, alcohol so if u're habits in what u eat & drink etc r not 'stable' it will affect u're INR ;0)

  • Good information, received the INReview magazine which has an article on YOUR DIET AND WARFARIN. Gives low, medium and high Vit K scores to most foods. This is a very good publication (for those on anticoagulants) and I have found it most helpful, along with this site, for the everyday challenges in recovering from a PE. Thanks everyone for your support and interest.

  • I have been on holiday long haul since My heart attack ( which was caused by blood clot )

    I asked and was given Clexane rather than Warfarin as it would be easier. All other usual precautions as well, water,socks, exercise etc

    I have a coagucheck machine it costs over £400 pounds, but as I am going to be on warfarin for life and with a target of 3.5 I think it was worth saving for

    I did have s lovely list of Vit K foods that I found on the net and try to eat the same amount everyday as this helps with Keeping INR regular well almost.

    It's very important to get insurance cover for any holiday as I am sure you know


  • Even know i cant help medically i know how you feel. I too am on warfarin and have fluctuating inrs. I was told i could be really good or stubborn but in 4 yrs i have only ever had about 5 appts with more than 3 weeks between. For the last couple of months I've been really good but lately have been going dr and i even added a 3rd day of 5mg but again i have gone down. Its only by 0.1 but my range is between 2.5 and 3.5. Not happy and a little worried.

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