Warfarin dosing gut check

[watson524]

Hi all,

My mom's been on warfarin for a bad native mitral valve and constant a-fib. Has been well managed where very few changes in dosage, changed from 4mg to 3mg / day back in March after a fall and short hospital stay. 2 tests ago (3 weeks) she was at 1.5 so her GP that manages the dosing had her take a double dose one day (so 6mg) and then get tested in two weeks. Got tested last week, INR is 1.7 so today the GP called me and said he wants a double dosage today and tomorrow and then test in 3 weeks. This seems asinine to me and I've long disagreed with his dosing methods. Adding an extra 6mg this week alone seems to me like it'd spike her way high and then 3 weeks later, that won't even have any affect because it'd be out of her system so the next test would likely show a range similar to what she's at now. I don't know the specific half life and of course it can be patient dependent but this just seems stupid.

I looked at the online calculator and it seems the better method is have her take 4 mg two days / week, 3mg the other 5 days, do this for each of the 3 weeks and then have her retested as planned.

I should add that her target range is 2.0 - 3.0

What do the wise folks here say?

thanks!

 

[dick0236]

Hi all,
This seems asinine to me and I've long disagreed with his dosing methods. Adding an extra 6mg this week alone seems to me like it'd spike her way high and then 3 weeks later, that won't even have any affect because it'd be out of her system so the next test would likely show a range similar to what she's at now. I don't know the specific half life and of course it can be patient dependent but this just seems stupid.
thanks!

I agree that the double dosing will spike her INR and be out of the system in three weeks. If she was well managed at 4mg/day I'd go back to the 4mg every day.......that's 28mg/wk. BTW, if I ever made significant dosing changes as he suggested I'd test after one week of such change, not three weeks.

 

[watson524]

Thanks Dick! Glad you chimed in given all your experience and knowledge. When she was on 4mg, she was running in the 2.5 - 3.5 range. That came up as a concern in our trip to CCF last year and again when she fell in March of this year and spent about 2 weeks in an inpatient PT rehab place. They both said that for native valve, a-fib needs, 2.0 - 3.0 was the recommended range (her heart doctor locally is also fine with that tho he doesn't manage the warfarin dosing) so I'd like to try to keep her in that range and if that means alternating between 3 and 4mgs on different days, we're ok with that. She has a weekly pill dispenser thing and is good about taking pills so I don't worry about confusion from non consistent doses.

Given that added info, does the +2mg / week sound reasonable knowing we might need a 3rd day with an extra 1mg to bump more to the middle of the range?

And I'm with you.... 6mg extra in a week and then wait 3 weeks to get tested, I would have expected testing in a week too. Geez.

Hope you're doing well!

 

[pellicle]

Hi

My mom's been on warfarin for a bad native mitral valve and constant a-fib. Has been well managed where very few changes in dosage, changed from 4mg to 3mg / day back in March after a fall and short hospital stay. 2 tests ago (3 weeks) she was at 1.5 so her GP that manages the dosing had her take a double dose one day (so 6mg) and then get tested in two weeks.

well the thing is that two weeks after the double dose she is likely to be exactly where she was before. I mean (as you mention later) it will be long gone, its like putting $10 in your car tank and driving around the week and expecting it to still be there. GP's frequently have not the slightest clue about pharmacokinetics (I'm sure he doesn't eve know what that means, try asking him/her)

Got tested last week, INR is 1.7 so today the GP called me and said he wants a double dosage today and tomorrow and then test in 3 weeks.

Einstines quote comes to mind: [h=1]“Two things are infinite: the universe and human stupidity; and I'm not sure about the universe.”[/h] To me trying the same thing and expecting different outcomes is stupidity.

This seems asinine to me and I've long disagreed with his dosing methods.

100% with you there ...

I looked at the online calculator and it seems the better method is have her take 4 mg two days / week, 3mg the other 5 days, do this for each of the 3 weeks and then have her retested as planned.

I should add that her target range is 2.0 - 3.0

What do the wise folks here say?

you don't mention if she has had the mitral replaced, but if that range is the one she has has been given, then stay with that range. Next I'd say to gradually up her dose and that strategy you outlined above is the simplest one. I would creep her dose up in small increments and after stabilisation time (something like 5 days) test again and determine the dose.

Your story is why warfarin is regarded poorly in outcomes - NB medical mismanagement. Also it highlights why self testing and self dosing is becoming popular. If you are inclined I would go buy a used Coaguchek XS on ebay and buy some strips online for testing. Do your own testing on your mum and manage her dose for her. Testing isn't hard and attaining the goals easy too. There is much written about the positive outcomes in modern self management. I have a blog post about INR management with a video here

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

it show the steps in self testing and shows that its not hard.

Just write it in a journal and if you use "a graph paper" A4 book you can plot it on the facing page. That information will help you make dose decisions.

Best Wishes

 

[watson524]

No valve replacement

I'd LOVE to have her do home testing (if but for nothing else than 30+ years of needle sticks every 3 - 4 weeks in the same spot because it's the only spot to get a sample easily due to rolling veins is crazy) but I've asked the GP about this and he said absolutely not. First I explained that it's not like he doesn't get the results and consulted for dosing but then he said he doesn't believe they are as accurate in their readings (which has come up with a few docs in the area I've asked). So that is out..... plus, she's had some significant falls in the past 18 months (no major bleeding issues but bruising badly as can be expected given the falls) and has developed some neurological issues (tho no clotting or bleeding stroke per multiple scans) so we're currently working on the neuro issues and trying to keep all else static.

 

[dick0236]

No valve replacement

I'd LOVE to have her do home testing (if but for nothing else than 30+ years of needle sticks every 3 - 4 weeks in the same spot because it's the only spot to get a sample easily due to rolling veins is crazy)

Why is she not getting finger sticks at her docs office? She's got ten of them and the sample needed is a small droplet of blood. Her GP is really operating in the "dark ages".........still using venus draws and not allowing home testing.......especially since you know, or could easily learn, the self-testing protocol . Medicare approves self-testing for mechanical valve patients and I've heard that has also been extended to A-fib patients who need frequent testing.

I looked at the dosing guide I use and for someone with a range of 2-3 and currently <2.0 it says....."Increase weekly dose by 10-15% and recheck in one week". That guide was developed by a pharmacist (now retired) who was known to be an authentic INR and warfarin expert.

 

[pellicle]

Why is she not getting finger sticks at her docs office? She's got ten of them and the sample needed is a small droplet of blood. Her GP is really operating in the "dark ages"..

I'm 100% with Dick here ... change GP ... I really do not understand why people stick with a Dr (who they've had for years) when they complain (legitimately) about his poor practice.

If he's practiced this long and hasn't got any better then he's a failure. Move on. Think of your mums health.

Alternatively just do it yourself and don't tell him. Strips cost $5.70 each so its really quite affordable.

 

[pellicle]

Hi

... but I've asked the GP about this and he said absolutely not. ... he said he doesn't believe they are as accurate in their readings

ok, this makes clear that he's an idiot who is out of date. Change, you will not change him. There exists an enormous wealth of studies to demonstrate beyond doubt that they are accurate enough:

For instance
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1860570/

[h=3]Conclusions[/h] In the hands of patients the CoaguChek XS showed good correlation with laboratory determination of INR and compared well with expanded and narrow clinical agreement criteria. Both patients and doctors were highly satisfied with the accuracy and ease of use of the CoaguChek XS.

http://archinte.jamanetwork.com/article.aspx?articleid=216393

definately download and read this one
http://mwdn-richmondva.cadmus.com/elsevier/1082533_404_wtrmrk.pdf

secondly there is such an overwhelming acceptance of this that many nations are restructuring their health care systems to promote home testing and monitoring.

So like the famous scientist Max Plank wrote:
"science advances one funeral at a time"

Sadly Doctors like this guy cause more before they leave practice

 

[Agian]

I've asked the GP about this and he said absolutely not.

Rhymes with tanker.

 

[pellicle]

Rhymes with tanker.

Reason was once King of Science ... now reason is dead and Wang is King
The King is dead ... long live the King ... Wang King

(oops)

 

[watson524]

Dick - do you use an online guide? I was using this one: http://www.pace-med-apps.com/CoumCalc.htm but perhaps I'll have her take an extra 1mg on Saturday too (so +3mg over the course of the week).

As for the doctor and that whole circus..... My mom's been going to him for over 20 years. There have been times where she's questioned him but this isn't one of them. She doesn't see the needle draws as a big deal and since I'm in "pick your battle" mode given her other recent, more urgent health issues, I have to let this one go I think. The kicker is he was a young doctor when we started going to him (other one had retired) so he's not old.... mid 50s... you'd think he'd be into the "new fangled technology"

And it's interesting, I think I did ask her cardio at CCF about it once and he wasn't too keen on the finger sticks either but I think her cardio here IS ok with them so if I have to, I'll play the card of the opinion of the local cardio who she's been with for 30+ years and trusts.

There was only one place locally that did the finger stick as far as I knew when I investigated before and that lab is now closed. We have the Geisinger system around here and I did just ask a friend that works in their heart hospital if they've changed from vein draw to finger stick recently. At least even if we're not testing at home, tho she doesn't mind the needles, i'd like to see her get the finger sticks done. Our doctor isn't part of Geisinger from an ownership status but his group is a "partner" so if they're doing it, that should give some credence to it and I would imagine institutions who use the finger stick method are using the same machines as we'd get for home.

 

[gregjohnsondsm]

I agree with everything that pellicle and dick have said. One needs to be vigilant and informed about their doctors and the doctors decisions. They make mistakes. My dosage finally ended at 7.0 for 5 days and 8.0 for 2 days of the week. And this after testing every week for 2 months. So the idea of two large doses and then testing after 3 weeks is ridiculous. I am certainly not an expert, not even very knowledgeable of this process, but even I am sure that this is bad advice.

INR Variations by test method: On another note, I was recently at my Cardiologist for bleeding and they used the finger stick method to test my INR and got 3.6. I was told to go to the ER where, of course they IV'd me and took a blood sample less than 1 hour from when I was at the Cardio. And the INR from that test was 2.9. I have not enough data to draw any conclusions other than either: 1) The methods do vary on their readings. 2) my INR can change very rapidly or 3) the operators technique of testing can cause variations of the readings.

 

[dick0236]

Dick - do you use an online guide? I was using this one: http://www.pace-med-apps.com/CoumCalc.htm but perhaps I'll have her take an extra 1mg on Saturday too (so +3mg over the course of the week).
.

No, the one I sometimes refer to was published by Al Ludwig, the pharmacist I referred to. Normally I make small changes based on my own experience and refer to his guide for "moral support". I NEVER make big changes as they, almost always, cause a yo-yo in INR.

 

[dick0236]

INR Variations by test method: On another note, I was recently at my Cardiologist for bleeding and they used the finger stick method to test my INR and got 3.6. I was told to go to the ER where, of course they IV'd me and took a blood sample less than 1 hour from when I was at the Cardio. And the INR from that test was 2.9. I have not enough data to draw any conclusions other than either: 1) The methods do vary on their readings. 2) my INR can change very rapidly or 3) the operators technique of testing can cause variations of the readings.

Any of the three reasons you've listed may be true.....especially #1 and #3:

1. Different measuring methods are used in venus draws vs finger sticks. The time lag between reading results can, and does, affect INR.......and which one is right??

2. I think this can happen altho I think the differences between the two testing methods is more likely the reason for the difference in INR readings.

3. I know this to be true....at least in my case. Lab samples, left too long, before sampling or finger stick expertise can have significant affect on INR readings.

Best to pick one method and stick with it. I home test but go to my docs finger stick lab a couple times each year to validate my meter. We both use the Coaguchek XS and are always pretty close in our readings.

 

[Boomanchu]

Well, I just got my CoaguChek XS delivered an hour before my INR check apt. @ 4:00 pm. I did mine quick and it came out 2.7, Let's see what it turns out to be at the cardiologists office. I think I got a great deal on ebay, new meter, 48 strips, a travel case and 200 lancets (plus 5 with unit) for $560 but only if it's accurate right?

 

[pellicle]

Hi

given that you are already on warfarin (the plural you of you and your mum) dosing is childsplay.

You have a range ... wiggles around within that range (perhaps temporarily out of it) are normal = do nothing
Your INR is low, heading low as a trend for a few weeks = increase the dose a small amount (no more than 10% maybe 5%)
Your INR is high, heading high as a trend for a few weeks = decrease the dose a small amount (no more than 10% maybe 5%)

you missed a dose? = slap on the wrist and proceed as normal
you accidentally took 2 doses = half the dose the following day + slap on the wrist + proceed as normal

myself (if you read my blog) I find that moving from 7.5mg daily to 8mg daily can correct a low and back to 7.5 or 7mg daily if I go high.

Its so simple even a Dr should be able to do it ... if not, just do it your self. I mean seriously, why not just do it yourself? $7 per week wouldn't even cover the fuel costs to drive to the doctors.

IF the Dr finds out (cos say your mum blabbs about it) show him the log and say ... see its more regular than under you.

..I did just ask a friend that works in their heart hospital if they've changed from vein draw to finger stick recently. At least even if we're not testing at home, tho she doesn't mind the needles, i'd like to see her get the finger sticks done. Our doctor isn't part of Geisinger from an ownership status but his group is a "partner" so if they're doing it, that should give some credence to it and I would imagine institutions who use the finger stick method are using the same machines as we'd get for home.

as I see it (my own view) resistance to this method is based on:
1) we are going to loose a very easy money for little effort money stream
2) some people are so untrustworthy and fruit-loopy as to be untrustworthy to tell you the time reliably off their watch
3) why lose money?

I have a school friend who runs a pharmacy, most of his clients are elderly. He barely trusts them to follow the directions on the box - which is based on 20 years experience with that demographic. There are of course exceptions and if you ask me you managing your mum is ideal. Finally, read my blog posts and have a go, its really quite simple.

Best Wishes
{PS: I manage my own INR and have done since relatively soon after surgery. I too got the irrits from the King Wang clinic management and I too have only one good vein. I have been more stable under my own guidance AND I have learned more and become less afraid. Knowledge is confidence}

 

[watson524]

I wanted to close the loop on my original questions from this thread. I took over the dosing for my mom and we've been able to keep her in a 2.0 - 2.3 range since May so I'll just proceed as we've been doing. She's at 4mg 4 days/week and 3mg the other days. The home testing thing is still a discussion in progress but given some neuro degenerative issues we're dealing with (new doctor, testing and hopefully Dx) we'll keep going to the lab for the draws and then hopefully once we get the more critical issues sorted/explained, I can get back to fighting this battle. Thanks for everyone's advice!