INR change

[Guest]

I just got my coagucheck xs in the mail today...read the booklet, made sure I did everything I was supposed to.
The reading I got was 1.9 compared to 3.4 at the doctors office last week.
I'm only on warfarin for about 2 and a half weeks now, Is this normal?
Last week I was on antibiotics and was told it could cause my levels to go off.
i have 7.5 mg tabs, after getting a 3.4 reading last week, I was told to take half of the 7.5 on Fri. & Sun. And a whole tab on other days.
My next doctor appointment is Tuesday , where I will be tested again.
i was planning on testing when I got home from the appointment on Tuesday and compare readings.

 

[dick0236]

Nope, going from 3.4 to 1.9 in one week is not normal.......but can, and does, happen. The reasons for such a swing may be due to:
a. your inexperience with using your new meter
b. the recent antibiotic which can affect INR. My INR usually goes down with many antibiotics.....but a 1.5 drop would be unusual.
c. the recent dosing reduction may have been to great....especially if you where still on the antibiotic
d. the fact that you are very new to warfarin and it takes a little time to establish the proper dosing

I assume your INR range is 2-3 and I would not worry much at either 3.4 or 1.9. Your idea to test after your doctors appointment is a good idea. That will tell you a lot. You should be within +/- .2.....with their meter. It will only be a coincidence if your meter reading matches theirs. When making dosing changes....take baby steps. Large increases or decreases of warfarin will cause a yo-yo effect on INR.

In a few weeks you will be an INR pro. BTW, welcome to this forum.

 

[LondonAndy]

I agree with all that Dick says, including the possible effect of the antibiotics, and also your plan to self-test again at the same time as your doctor's appointment on Tuesday. Provided the drop of blood you applied to your CoaguChek test strip was applied promptly (eg you didn't have to spend a lot of time massaging the finger to get a sufficiently large drop of blood), there is not much that can go wrong with a home test, and to my mind there are more variables with lab tests. So if the test at your doctor's is a blood draw (as opposed to them using their own finger-prick machine) it is also possible that their reading was not as accurate as your home machine's.

Unfortunately it will take time to see what effect different issues have on your INR, and in the early days I found that I sometimes did additional testing to see what effect things had, eg when I had a cold, or some alcohol, before settling on a default weekly testing regime.

 

[Warrick]

i was planning on testing when I got home from the appointment on Tuesday and compare readings.[/QUOTE]

Thats what I did for quite a few weeks when I started self testing also, It took a bit till I was getting readings consistantly the same or similar to the lab, now I confidantly fly solo with my meter.

I think that the antibiotic sounds like the most likely culprit, I'd guess if you google the antibiotic warfarin interaction you'll have your answer. I've gone from INR 2.2 to INR 6.3 in 3 days on an antibiotic, so not unexpected to see a big change from what i can see.

 

[pellicle]

Hi

I just got my coagucheck xs ...The reading I got was 1.9 compared to 3.4 at the doctors office last week.

firstly I think everyone has raised sound points.

Next its important to remember that measurement of INR is not like pulling out a tape measure and measuring the length of a block of wood, or weighing something and knowing how many grams (or Oz) it weighs). Those things are more precise. So lets look at a publication: [IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/c2.staticflickr.com\/6\/5784\/21878002284_075c4a55ce_b.jpg"}[/IMG2]



so from the same actual blood sample those methods gave ranges from 1.99 through to 2.4

next we don't know (or I missed it) how many days passed between your sample and their sample.

So while this variance (your stated variance of 1.9 through to 3.4) isn't normal, it is clear from the above that its not out of the possibilities given time between sample (allowing for natural variation) and variation between methods of assessment (allowing for method variance).

I'm only on warfarin for about 2 and a half weeks now, Is this normal?

so its likely you are still setteling in ... as has been mentioned by other responders.

Last week I was on antibiotics and was told it could cause my levels to go off.

it indeed can ..

My next doctor appointment is Tuesday , where I will be tested again.
i was planning on testing when I got home from the appointment on Tuesday and compare readings.

a wise plan ... test within hours of the lab blood sample (NOT OBTAINING RESULTS) and then compare the results.

Please post back

Best Wishes

 

[pellicle]

to Guest ... this is an important point

.... Provided the drop of blood you applied to your CoaguChek test strip was applied promptly (eg you didn't have to spend a lot of time massaging the finger to get a sufficiently large drop of blood), there is not much that can go wrong with a home test, and to my mind there are more variables with lab tests.

and feeds into Warwicks point.

If coagulation begins (after the drop is forming and before applied to the strip) then the Coagucheck will measure the time from when it got the blood to coagulation and report a reduced time, thus a lower INR. Follow the 15 Second Rule.

From the manual:

[IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/c1.staticflickr.com\/9\/8204\/8282903885_11ae842b24_b.jpg"}[/IMG2]

and

[IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/c1.staticflickr.com\/3\/2829\/13854286175_190c468489_o.jpg"}[/IMG2]


As Dick says, soon you'll be expert.

Follow a process, be careful and repeatable. My video (on my blog, of taking my INR) is also a good idea for you to do for then you can video it too (put your phone on a stand and record it) as then you'll also have accurate time measurements of the process and can watch what you do dispassionately later.

Best Wishes

 

[Jimmyk]

I wasn't signed in when I posted.
After seeing such a big drop in my INR, the first thought was that I may have bought a defective machine on eBay. Then again, it might just take a little practice to master this at home testing.
The first test, I wasted a strip. The drop of blood was too small, and my machine said error 5.
The second time I didn't massage my finger, I just pricked it, squeezed, got a nice drop,but it says to place the drop on the strip within 15 seconds. Not sure if I went over the 15 seconds.
The clinic that I went to last week, a machine was also used to do the test. It was a coagusense.
Ok, don't mean to ramble, like i said, I'll test on Tuesday when I get back from the doctors office and compare.

 

[Warrick]

I wasn't signed in when I posted.
After seeing such a big drop in my INR, the first thought was that I may have bought a defective machine on eBay. Then again, it might just take a little practice to master this at home testing.
The first test, I wasted a strip. The drop of blood was too small, and my machine said error 5.
The second time I didn't massage my finger, I just pricked it, squeezed, got a nice drop,but it says to place the drop on the strip within 15 seconds. Not sure if I went over the 15 seconds.
The clinic that I went to last week, a machine was also used to do the test. It was a coagusense.
Ok, don't mean to ramble, like i said, I'll test on Tuesday when I get back from the doctors office and compare.

Dont worry about rambling.. we've all been there how are you getting on with comparing tests ??