Sudden drop in INR

[Thomas]

Hi,
I'm at a bit of a loss on this one. I've been on Warfarin for just over a year holding at my target INR between 2.5-3.5 without any issues. All of my testing has been at the same lab, same weekly day and time. I don't self-test yet.
Yesterday my regular test was done and my INR had dropped from 2.7 (2 weeks ago reading) to 1.5 . It had been steady with very minor fluctuations over the period I've been taking it. No doses were missed and nothing in my routine has changed and I don't get it.
I went back to the lab this morning to be re-tested thinking there might be an error in the sample reading or even a plain old typo in the email result. We'll see.
I'm just wondering if this is a relatively common occurrence or just a weird one-off because of.... I don't know, crappy weather...?
thanks
Thomas

 

[tom in MO]

It's happened to me a few times. Just recently I dropped to 1.5 (range 2-2.5). I home test and it is always the same upon retest. Sometimes I go back to normal with just a booster dose for a day or two. Sometimes it goes to a new normal as in this case. My dose went from 4mg M/W/F 4.5mg all other days to 4.5mg every day.

It can be nerve wracking if you worry. I assume they upped your dosage and want you to test in 4 days to a week. That's what they do with me. Don't worry, just lay off the salads for awhile and take your meds. Don't forget to test. You'll be OK.

 

[dick0236]

Hi,
I went back to the lab this morning to be re-tested thinking there might be an error in the sample reading or even a plain old typo in the email result. We'll see.

It can happen, but fortunately, not often. Smart idea to retest before making any change and go from there.

BTW, I have never had that kind of INR swing "just out of the blue". More often than not it has been test problem.

 

[Thomas]

Thanks guys.
I got the test result from this morning and it's 1.8. So that tells me there wasn't an issue with the test yesterday. Something has gone weird with me. I spoke with my doc and he said to bump up the dose 2.5mg for today and then stay steady at my regular 10mg dose until next test.

 

[pellicle]

Hi

first yes it happens, but like has been suggested by the other guys its a personal thing. One of the other members here ( Warrick ) is like Dick and also has an INR that seldom varies much. I have a body which likes to make changes when it feels like it.

Hi,
I'm at a bit of a loss on this one. I've been on Warfarin for just over a year holding at my target INR between 2.5-3.5 without any issues. All of my testing has been at the same lab, same weekly day and time.I don't self-test yet.

thats good to hear that you're being super regular with your testing regime and also good to see the "yet"

Yesterday my regular test was done and my INR had dropped from 2.7 (2 weeks ago reading) to 1.5 . It had been steady with very minor fluctuations over the period I've been taking it. No doses were missed and nothing in my routine has changed and I don't get it.

I see that sort of variation in my INR, especially given that it was over 2 weeks. This represents a movement downwards which if was a simple steady daily drop would only need 0.085 INR units per day. If you think about this this way its actually no a sudden drop (and with two weeks in the middle you have no idea if it was sudden or gradual). This underscores why I do not support longer testing schedules and why I support weekly testing. Were you weekly testing you would have seen this much sooner and most probably before it went below 2

I went back to the lab this morning to be re-tested thinking there might be an error in the sample reading or even a plain old typo in the email result. We'll see.

I also think that a retest is a good idea, not just because its a double check, but because of the long duration (2 weeks) between tests you have no idea if it is working its way back up or still trending down. Knowing that makes a big difference to how to respond with adjustments in dose.

I'm just wondering if this is a relatively common occurrence or just a weird one-off because of.... I don't know, crappy weather...?
thanks

well you've only been on warfarin a little while yet, so you're probably still going though some changes in body. Myself I had a number of changes in the 3 or 4 months after my surgery, which is actually quite well known and experienced managers of INR should be well aware of it. My own dose changed from 4mg over that time to 8mg (which I now more or less am on).

I recommend holding your hand momentarily on dose changes but you should be aware that 1.5 is not an INR you want to sit on very long, I would strongly counsel you to increase that in the next 48 hours at most. So don't let them dally you around with your results. Depending on the findings please post back here ASAP to discuss what happens (even IF they already have a plan for what to do)

BTW who is managing your INR, surely they went spastic on hearing that 1.5 by now already.

Lastly here is one of the graphs of my INR that I make when I do my self testing (and indeed full self administration of dose)

when reading through that chart be aware the dose axis is on the right and the INR axis on the left. You can see INR changes and subsequent dose changes in weekly readings there. As it happens when my INR goes out of range I also do a mid week test to confirm and guide my decisions.

Best Wishes

 

[Thomas]

Thanks for all the feedback. I normally go every week for testing however I've been traveling a lot (typing this from 30,000 ft. right now) and had to miss the last test. I really have to get moving on self testing to avoid this situation.

The strange thing regarding trending is that I had been on a slight upward curve for a month and then over the course of 2 weeks went in the opposite direction. I can't attribute it to anything diet or lifestyle related.

I spoke again with my doctor this morning and he's a bit perplexed on the change as well. We're in agreement on a quick approach with dose increases and increased testing frequency short term.
I'm going to be retested on Saturday and then again next Tuesday to keep a tight rein on things until things are back in range.

 

[pellicle]

Hi

glad its all working well.

when / if you get into self testing (and maybe self management so you don't need to fret about anything when its not "regular" I have a blog post which (if you haven't read it already) I believe is a good reference guide.

http://cjeastwd.blogspot.com/2014/09/managing-my-inr.html

...The strange thing regarding trending is that I had been on a slight upward curve for a month and then over the course of 2 weeks went in the opposite direction. I can't attribute it to anything diet or lifestyle related. a tight rein on things until things are back in range.

the thing about trending is that trending only makes sense if you have an underlying known cycle (and longer terms). To say that the stock market is trending up is not a wise way to conduct buying (or defer it). Look again at the trend lines of my chart above and you'll see trending up and trending down. There is nothing I've examined in my 7 years of this that is repeatable.

Also, ask your doctor how much they actually know about managing INR and how many patient over how many years they have managed successfully. (normally this is way outside of scope for doctors) Most just bumble through on the fact that "it'll sort itself out" (which it will mostly). But its important to keep clearly in mind that the best outcomes are had from being in range more than not. So being in range > 90% of the time is desirable.

Best Wishes

 

[LondonAndy]

Firstly just to say that if your regular dose needs to be amended to a slightly different amount that is not a problem according to my Cardiologist here in the UK - when I mentioned that I had had to reduce my daily dose (I self manage) from an alternating 7 and 8mg each day to 6 and 7mg each day he was totally relaxed about it. For me, significant changes to my INR have occured when I have a cold (INR drops) or when I am on antibiotics (INR rises).

Self testing is a doddle, as we Brits say - ie easy. I am currently on vacation in the Canary Islands, escaping yucky winter at home, and naturally I have brought my meter with me in my hand luggage. You mention "crappy weather" and I do wonder if there is something in that. Here it has been 23 to 28C or more, compared with -2 to +6C at home (74 to 83F and 28 to 43F respectively) and I have had to reduce my Warfarin dose here by another 1mg per day. However, that could also be because of a significant change in diet and increased alcohol consumption - everything in moderation though, honest doctor

 

[LondonAndy]

TWO further thoughts:

1. UPDATE - I realised after posting that message that I hadn't retested my INR for about 5 days, and so did so (at 8am from the comfort of my sun terrace, where I am sitting in some rather fetching swimming shorts. No need to get dressed and find a clinic on the island at this early hour). Today's reading is 2.3, so looks like I slightly over reacted to my 4.3 result last week (I skipped a day's dose as well as reducing daily doses thereafter by 1mg. Conclusion: small course adjustments only in future).

2. If my INR had fallen to 1.5 my surgeon felt passionately that a change to Warfarin dose was not responsive enough, and that I should have Heparin injections in addition to the Warfarin until back in range. When such an event occured I tried to do this though my anticoagulation clinic but they refused, so I went back to the surgeon, explained, and he wrote a prescription for the Heparin on the spot. I tend to aim for my INR to be 3.0 to 3.5. I am more concerned about going below range than going above, precisely to leave some room for a significant reduction event.

 

[tom in MO]

...2. If my INR had fallen to 1.5 my surgeon felt passionately that a change to Warfarin dose was not responsive enough, and that I should have Heparin injections in addition to the Warfarin until back in range. When such an event occured I tried to do this though my anticoagulation clinic but they refused, so I went back to the surgeon, explained, and he wrote a prescription for the Heparin on the spot. I tend to aim for my INR to be 3.0 to 3.5. I am more concerned about going below range than going above, precisely to leave some room for a significant reduction event.

Your profile indicates a St. Jude at the aortic position. I have the same valve manufacturer and position. Recent studies on St. Jude valves have led to a lowering of the therapuetic range from 2-3 to 2-2.5. In addition, I had a surgery and was off warfarin for a few days, dropping to 1.5. My cardiologist did not require Heparin. I questioned that and he indicated that there is a lot of data on the St. Jude product and that it's quite stable allowing a drop to 1.5 for w/o worry. Possibly your anticoagulation clinic might be a bit more up-to-date than your surgeon.

 

[LondonAndy]

Thanks Tom, useful info. My low INR occured in about December 2014, so if you say the research is recent perhaps it has become more comprehensive since then? But having had the valve inserted in something of an emergency situation I was more inclined to go with his advice rather than a clinic nurse. I will do some research myself but sounds like good news - thanks for the feedback.

 

[Thomas]

Hi all,
Here's an update.
Since I had the initial result of 1.5 and then retest the next day with a result of 1.8, I upped the dosage from 10mg to 12.5mg the next 2 days, then back down to 10mg steadily. I was retested on Tuesday just past and my INR went to 2.6. Just shows how much difference a little dosage adjustment can make.
So it's back in the theraputic range and headed the right way. I'm going to leave the dosage consistent and see where I land with the next test scheduled Tuesday coming.
Hopefully things are level or a little up. I'd like to stay closer to 3.0

 

[Nusb22]

I had opposite problem on my last check, mine was higher. It was cause by a change in diet. Was trying to eat healthier, salads ect... Green leafy veggies are high in vitamin K, which affects INR, so I've been told

 

[pellicle]

Hi

I had opposite problem on my last check, mine was higher. It was cause by a change in diet. Was trying to eat healthier, salads ect... Green leafy veggies are high in vitamin K, which affects INR, so I've been told

except that you don't know it was the cause and suggesting green leafy veggies as the cause goes counter to what the effect on INR is, IF your diet had any effect (which I highly doubt it did) the INR should have gone down not up.

All too often on this forum you'll find the stories of advices given by "professionals in the know" boil down to "they don't have a clue"

You will find repeated here by those of us who are on warfarin to eat a healthy diet, monitor your INR and adjust. Attempting to read into results being caused by what you did is fraught. All too often people make one observation (not dozens) and make the causal link when it is no more than a coincidence.

Myself I've been making weekly (or more frequent) readings of my INR since 2012 which I write up and have every reading on a spreadsheet, and I'm unable to make any clear association with "I ate a salad" and my INR.