Mechanical AVR, aortic reconstruction and single bypass in 01/2021. Obviously wafarin for life. Self tester with home kit since December 21.
My question is when I test my INR levels can change from one day to the next. Be aware I only do this when I am out of range, I only test once a week otherwise.
When I first started on this I was told that it would take 2 to 3 days for INR levels to alter but my level has been 3.8 one day, 2.9 the next, 3.6 the following day and 2.7 after that.
I generally stay in range but when I go out of range it really jumps about and can take a week or so to steady back up. I am my worse enemy on the rare ocassion as 3 times in the past 3 months I have missed my dose, which has meant my having 18000 ul fragmin (heparin) injections for a few days to counteract the missed dose.
Sorry I've just checked above and even I cannot see a question there. Does anyone have a similar experience and has anyone been able to manage it better than I am currently. Can I ask no-one answer with the old "don't miss your dose then" I'm looking for experiences not treated as a fool, I already feel like that.
Morning, I've been on warfarin for 10 years now, having had an avr and a resection, I'm not a home tester, so tbh wouldn't have a clue what my INR is doing in between visits to my GP practice for testing, but, what I would say, is that consistency is the key to good balance, try and keep meals as similar as possible, try not to change your diet too much.And personally if I miss a dose of any medication I just take my next dose as normal, not, that it's something I make a habit of. I've never been advised to take fragmin for a missed dose.
I personally think the fluctuation you are seeing is unlikely to be due to a missed dose. The half life of warfarin is variously reported as between 24 and 76 hours, so inherently relatively slow-acting. This site: drugs.com/pro/warfarin.html suggests as the effect of warfarin lasts a fair time, that if missing a dose, taking it the same day will be ok, but not to double up the next day. (I take mine in the evening, so if I find in the morning I missed last night's, I just take it asap in the morning.)
As you'll know, it's a vitamin K antagonist, so things that vary your vitamin K will make your INR change (details down the page on the same site). The classic ones are leafy green veg. There are others. The rules are not that you shouldn't have such foods, just that if you do you should keep your intake relatively consistent day to day, (no binging on kale, as if anyone would 🤣).
Having large quantities of something containing vitamin K would account for your INR dipping down. I'm less sure why it would peak again afterwards.
I wonder if your self-testing result might vary from time to time due to non-INR factors? I've ask my warfarin nurse here about self testing and whilst NICE says self-testing can be done, she is less enamoured about it and has said that there are numerous factors which can change a reading. For example, I forgot and accidentally used hand gel on my way in to the surgery the other day, but remembered prior to the sample, and she had to clean the finger site very carefully before sampling. I'm sure that there will be many other factors. Also, the machine should be periodically calibrated against a veinous sample. And finally, technique has an effect.
I don't know if you could raise this issue with your own warfarin clinic?
Thanks both for your replies.Cliff, you raise se interesting points, I am unaware of eating anything containing vitamin K however that doesn't mean I am not.
I agree, I don't think it is missing the odd dose, this does make my levels drop, I had a stroke last August which I would like to say was from my INR being too low ( my INR when my son took me to hospital was 2.1) however as I have never recieved any type of follow up whatsoever I couldn't tell you definitively.
Post stroke I was told my range will rise to 3.0 to 4.0. Hence my concern over fluctuating levels.
My home tester is great, it has to be calibrated every 3 months by the surgery and I went through a 2 hour session to ensure i was doing the testing properly. I can only say each to there own with usi gmor not using these. Due to my work situation and the fact the surgery have stopped evening appointments as they don't have enough staff this has proven the best way to test.
I am determined to make sure I take the bloody things every day, and have now placed odd packs in my wallet, in my car and at work so when phone alarm goes off at 7pm, I will now always be able to get to at least my wafarin.
Hello, my husband has been on Warfarin for 4 years following his AVR with a mechanical valve. He home tests too and finds doing so it really useful. Fortunately he’s generally stable. I think the “secret” is to have a wide range of foods in your diet, aim for 30 different plant sources each week (including herbs and spices), include 1 portion of leafy greens such as cabbage or broccoli every day as vitamin k intake has been shown in a clinical study published in 2019 to stabilise INR, exercise most days, enjoy alcohol in moderation (it increases INR) and don’t worry overly! Easier said than done, but it does help. My husband also takes Ubiquinol every day to help his heart generally.
Have you seen the info sheets on the AF website? They’re worth a read. Here’s the link
Some people are naturally unstable. Many stable people go through seasons of instability. Constant fiddling with doses makes things worse (micromanagement). Consensus is that you need to keep above 2.0 to gain protection against clots, and that up to 5.0 is not dangerous.I have been self-dosing for over 28 years. You may find my latest paper on this interesting. Lowe, I. (2022). Critique of warfarin dosing: the use of nudging to adjust the load. Academia Letters, 2-8 academia.edu/76342271/Criti...
Quick history about me for some context: 4x CABG and aortic valve replacement (mechanical) in July 2013. In November 2019 severe nose bleed requiring a spheno palatine artery ligation surgery. My INR was 4.8 at the time but I wasn't self testing and sometimes going for up to 10 weeks without a test by the clinic. My target range was 2.5-3.5. Jan 2020, I became a self tester and never let it go more than 3 weeks between tests.
My experience of INR variation is that it is possible to test too frequently. If I am out of range, for example 4.1 during a test, rather than reduce the dose permanently which would probably lead to an over correction, I find it better to take a half dose that evening and stay on the normal dose for 1 or 2 weeks before testing again. When I have done this I am usually back in range on the next test without any permanent adjustment to dose. I don't think anyone knows how rapidly INR changes, but I suspect that it varies throughout the day, never mind throughout the week, but we can't take a reading every hour to find out because the sticks are so expensive. If you have been stable for a while and suddenly find that you have drifted a long way out, it is probably better to consider the reading to be a possible rogue reading and take action as I have done by taking a half dose, but don't test the next day to see the result, I would leave it a week at least or possibly two before testing again. I am of the opinion that dose adjustment can take a whole week to finally stabilise rather than the often quoted 2-4 days.
Missing doses is really going to screw up any plan for staying in range and I see you are already using your phone alarm to remind you. I also do this but I am not always right next to my phone so I don't rely totally on it. I have bought a cheap but fairly nice looking watch from e-bay with an alarm and that is set for the same time as my phone alarm. I can't remember the last time I missed a dose since I have been doing this. I think I would have to be in the shower to be away from both my phone and watch. I have probably thanked my watch half a dozen times for reminding me to dose up this year so far. I hope this helps.
I agree Wingnutty: do not test too often. I agree, do not worry about it if you are a little out. Anything from 2.0 to 5.0 can usually be left to self correct.
I find it fascinating when you say "I find it better to take a half dose that evening and stay on the normal dose for 1 or 2 weeks before testing again." This is what I call "nudging". It is like a reservoir which is leaking, and has a little stream for top-up. Sometimes the level in the reservoir needs adjusting, but the input ie the warfarin dose stays the same.
It is always safe to nudge, then test again 1 or 2 weeks later. Only if nudging does not work, then try nudging and a dose change.
I think a lot of the instability problems arise because people do not adjust the reservoir before they adjust the dose.
Thanks to everyone for there thoughts, help, really interesting reading advice and general well wishes. Sharon, hanibl and ilowe I will read up on this subject with the info you have supplied.Wingnutty, I agree totally, I thought back in December, when I first purchased my home tester, my GP sponsors the testing strips, I became obsessed with checking by the day.
I must say in defense of my current testing regime, my INR nurse is directing my checking, dose changes and heparin injections.
As I mentioned earlier, the stroke ( I considered this a TIA as it lasted 45 minutes, and I recovered fully, but the hospital insisted the CAT scan confirmed a stroke) I had has constantly put.me on edge, mostly because I haven't been told what the root cause was, so I have basically assumed it was my INR level being low. This is something the hospital must have thought (or didn't care) because my range was risen to 3.0 to 4.0 after this.
I am now of the opinion that my INR nurse is maybe as inexperienced of home testing as I am, I believe I am the 3rd person to use this method.
When I am in general range I take 5-6mg per day. If my level goes below 2.6, the nurse insists I take 18000ul fragmin injections, which they have prescribed in a multipack and I self administer. She will then raise my wafarin to 7mg. If I am over 4.5, she has in the past told me to stop for a day, however I did do this once and when I tested ( under her instruction) the next day it was 3.0, she then changed her mind and told me to continue on 5mg. The next day's test was 2.8, etc, etc.
Yes I agree, I am just one of life's unstable INR levellers. As I said I will not miss doses again, this definitely doesn't help my situation.
Genuinely, thank you all again, very much appreciated.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
Inr dropping. 
Testing my INR at home
Fluctuating HR post valve op?
Inr blood test
INR home testing 
