How much warfarin do you take to get to an inr of 2.5 to 3.5?

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I have had to take what I think is a shocking amount of warfarin for almost 3 years now, about 102 mg a week on average. Its shot up to 115 a few times and been as low as 95. What compelled me to post this though, is I decided to stop all alcohol about 5 weeks ago now, and expected that might cause my warfarin need to climb a bit. It's jumped to taking 107.5 and my inr has dropped to 1.4. So I am nudging it up to 17.5 3 days in a row and 15 the rest of the week to see what that does. Testing 1x a week.

I stopped the alcohol because I want to lose weight and get off bp meds and also start running more. I am down 7 lbs and already stopped the bp meds. I'm not touching the alcohol until I am down about 15 lbs.
As mentioned by others, everyone is different (and your dose is much higher than mine). I've been at 7.5mg per day for a few years and am only chiming in due to having given up alcohol this year. I haven't seen a tangible change in my INR pre- and post-drinking but, of course, YMMV. I've also been on the wagon for only five months although I would think that would be plenty of time for a trend to appear (testing weekly).

I'm an organic gardener and landscape nerd so spend a lot of time outside in the heat. One too many trips to the ER for tachy convinced me to finally give up those post-lawnmowing beers (and those I'd have for any other excuse). Being a homebrewer, that hurt on many levels but my cardiologist was overjoyed that I'd taken alcohol out of the health equation. Alcohol is obviously a cardiac stresser and at my age it was an unneeded demand to place on my heart.

Good luck with your weight loss and reducing your medication needs, it's a journey but one worth taking.
 
I "party" and don't have blood in my urine :)
But thats Missouri partying, not Louisiana partying. Pretty sure there's a good bit of difference, but Columbia is (was) my last stop in the SEC before OK and TX join us next year. Of course @pellicle is an Aussie, so he's probably got us both beat.

Probably not a stone though as most people describe that as pretty painful.
 
I’m currently taking around 18mg/day. I’ve come to terms with the high dosage and now focus on the INR value as the desired out come.

It is however annoying that warfarin is only prescribed at 5mg tablets with nothing stronger available. My GP has prescribed 3 x 5 bottles, reducing overall trips to the pharmacy.
 
It is however annoying that warfarin is only prescribed at 5mg tablets with nothing stronger available.

That’s not true. They also make 6mg, 7.5mg, and 10mg tablets.

I take 11 right now … and for me that’s a 10mg and half of a 2mg. I use half of a 2mg instead of a 1mg so that I can adjust upwards easier if needed.
 
And they make from 1mg to 10mg and you are dosed according the Protime or INR results. People like some doctors are not very well educated on the dosages available. I take 5mg 4 days a week and split the five to 2.5 the other three days of the week. Sometimes I hit the target and sometimes not.
 
And they make from 1mg to 10mg and you are dosed according the Protime or INR results. People like some doctors are not very well educated on the dosages available. I take 5mg 4 days a week and split the five to 2.5 the other three days of the week. Sometimes I hit the target and sometimes not.

To me, Caroline, I think it makes complete sense why you’re not hitting target. You are quite literally decreasing your dosage by 50% for 3 days … and then doing a 100% increase. Those are quite huge swings in dosage and will definitely result in complementary swings in INR.

I am not being argumentative or critical. I’m truly just trying to be helpful. You’d probably be better off just taking 4mg once a day, every day.
 
That’s not true. They also make 6mg, 7.5mg, and 10mg tablets.

I take 11 right now … and for me that’s a 10mg and half of a 2mg. I use half of a 2mg instead of a 1mg so that I can adjust upwards easier if needed.
Unfortunately not in Australia - largest dose of Coumadin/Marevan is 5mg with 1mg & 2mg also available. All sold in 50 pill bottles.
 
To me, Caroline, I think it makes complete sense why you’re not hitting target. You are quite literally decreasing your dosage by 50% for 3 days … and then doing a 100% increase. Those are quite huge swings in dosage and will definitely result in complementary swings in INR.

I am not being argumentative or critical. I’m truly just trying to be helpful. You’d probably be better off just taking 4mg once a day, every day.
You are being very argumentive, for I have been on warfarin for 22 years and counting. I have been more helpful on knowing the dosages and they come on 1 mg to 10 ng. Please realize that many of us have been dosing for many years here and know what we are talking about. And I do not take 4 mg every day. I take 5 mg four days a week and 2.5 mg three days a week. 100%. Be nice and stop trying to argue with us pros who know how this works.
 
And I do not take 4 mg every day. I take 5 mg four days a week and 2.5 mg three days a week. 100%.
carolinemc,
Why are you taking "5 mg four days a week and 2.5 mg three days a week" and NOT taking "4mg every day"?

This may work in your individual situation but for the benefit of others, especially newbies, the "ideal" regimen should provide the same dose, or as close to it, every day when possible except when a maintenance dose is required based on testing results.
 
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A comment to those who are taking significantly different doses on certain days:

Depending on the day that you test your INR, it may vary significantly. For example, testing three days after a dose of 5 will probably be considerably different than a test three days after taking 7.5 mg. Chuck M can get the same 'weekly' dose (and I'm using weekly just as a measure of what you get over a 7 day period, and because you're taking different doses on certain days of the week, your weekly total is 42.5. To reach the same dose daily, it's fairly easy to take mg a day (5 mg plus 1 mg or 4 plus 2). Try this first - if your INR is too low on 42 mg/week, add .5 one day of the week and see what happens three days after this minor addition.

Gail in CA - you're taking 45 mg/week. Like Chuck M, you can get an almost consistent daily dose by taking 6.5 mg a day (this totals 45.5 a week). I sometimes take this dose - a 4 mg plus 1/2 of another 4 mg, plus a half of a 1 mg (although there are other ways to do this). You may try the consistent dose and see if this raises your INR out of range (it probably won't), and if you're really worried about not taking exactly 45 mg/week (by going .5 over), you an omit .5 one day during the week.

Weekly totals are okay as long as you keep your daily doses as much the same as you can, every day of the week.

No - I don't expect that anyone would rationally take one weekly dose every week - but as we've seen here (and I was guilty of this decades ago), not taking the same daily dose is not uncommon and CAN cause your INR to vary depending on the dose from three (or so) days earlier.
 
you can get an almost consistent daily dose by taking 6.5 mg a day (this totals 45.5 a week). I sometimes take this dose - a 4 mg plus 1/2 of another 4 mg, plus a half of a 1 mg (although there are other ways to do this). You may try the consistent dose and see if this raises your INR out of range (it probably won't), and if you're really worried about not taking exactly 45 mg/week (by going .5 over), you an omit .5 one day during the week.
this is an interesting point and deserves teasing out.

46mg a week = 6.57mg a day, which would essentially be 6.5mg a day
45mg a week = 6.42mg a day, which isn't really obtainable in any fashion

yet it would appear to the casual user (drug user) that 45 and 46 may be different in outcome but by how much would not only be hard to quantify it would be difficult to actually do in any even fashion. So I get back to my view that thinking weekly obscures what's going on and doesn't help you with the practical thinking of how to handle the dose that you'll actually take each day. Another calculation is needed to work out how to administer the weekly dose.

I also get back to there is nothing in this which helps you to understand what's going on and to have a good estimate of how to change your INR based on the dose.

Below is something which emerges from understanding daily dose, and my Model of the regular weekly periodic measurements of INR

1701803915964.png


This isn't my data (nor is it likely to fit you), but its the same principle. You can see based on the Model, the Model factor emerges from the simple act of taking a weekly reading and writing it in the sheet. From that M you can then look across the chart and determine the daily dose that will achieve your goals (for instance if your Model was 4, then 3.5mg is indicated by the Model chart for someone with an Aortic valve and a target INR of 2.5. The colours guide you as to the "standard" range of 0.5INR units either side of Target.

So my approach (which emerges from daily dose thinking and weekly periodic measurement) has the following benefits
  1. a structured approach to actually recording your weekly INR
  2. the structure encourages regularity and a clear presentation of when you've failed to make a measurement by a gap in the data
  3. the INR that you record enables you to see what's happened and then feed into your decision of:
    a) remain on that dose again for next week (most common)
    b) raise the dose a smidge (and get guidance of how much)
    c) decrease the dose a smidge (and get guidance of by how much)
  4. make that dosing decision and move on to next week where you test and document again

HTH
 
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Over several decades, I have maintained an INR of 2.5-3.5 (or close) on 5mg/day with a few +/- 2.5mg to correct any trending hi or lo. About 18 months ago I started to drink a bottle of Boost to help with weight gain. Boost contains vit K and my INR took an immediate nosedive to +/-2. After spending some time alternating dosages I settled on 6mg/day(42mg/wk). After a couple of months on the straight 6mg schedule, my INR has (pretty much) settled into my 2.5-3.5 range skewed towards the high end(3.5).....where I like it.

I do not try to super-fine-tune my INR by taking a lot of different warfarin dosages throughout the week. The more dosages I have in my medicine cabinet.......the more chance of error. One strength, 6mg, solves my problems by providing 0, 3, 6 mg with one 6mg strength. I have not found a need for 9 or 12mg......so far.
 
y with a few +/- 2.5mg to correct any trending hi or lo.
indeed, a single correcting dose is always a good first strategy before considering an alteration.

Exactly by how much is either something learned (a heuristic) with careful attention or suggested by the data and a simple model.

However, you have the benefit of many decades of doing this and probably a doctor (who may not have known much more than you) to guide you. Over time this has put you were you are now.

What about those just starting out? Were you anxious about things from the start?

Knowledge is power, and IMO from that power comes a bit more confidence.
 
Sorry, Pellicle. That model looks like a puzzle - for me, at least, it took a while to figure out. I suspect that it may be a similar puzzle for many of us.

The reason I used a weekly dose for calculation of daily, consistent dosing, was because the people who reported their dosing did it weekly (like, for example, one dose on Tuesday and Thursday, and another dose the other five days of the week. I took the 7 day dose (which was where the dosing repeated) and divided it by 7 to get what should be a daily dose.

Although these calculated daily doses don't always come out to whole numbers of half numbers, I did a bit of rounding to achieve whole or half numbers - and recommended trying to slightly round up or down and see what happens to INR.

Although the idea of 'weekly dosing' is somewhat archaic, using a week as a convenient place to start repeating dosing makes it easy to calculate what the daily dose should be. Weekly dosing is fine - as long as the focus is on consistent daily dosing to reach a weekly total (rather than an inconsistent dosing schedule where lower doses are made on certain days).

20 or 30 years ago, it was considered okay (IIRC) to use a schedule like I used to follow where I took 7.5 mg on days with a 'T' in them and 5 on the other days. It worked for me -- but I wasn't concerned with self-testing or, for that matter, INR.

With the ability to self test today, I was trying to point out that if dosing isn't equal day to day, results will depend on WHICH day you test. +
 
However, you have the benefit of many decades of doing this and probably a doctor (who may not have known much more than you) to guide you. Over time this has put you were you are now.

What about those just starting out? Were you anxious about things from the start?

Knowledge is power, and IMO from that power comes a bit more confidence.
I did not intend to minimize the importance of properly managing ACT. That said, I think we sometimes make ACT overwhelmingly difficult for a new person on warfarin.

When I had the surgery I had never heard of Coumadin(warfarin)....INR had not been developed.....the only testing was done with a blood draw at the elbow hopefully not more often than once per month (it hurt).....and my PT(pre INR) was targeted at 18 seconds, 1-1/2 times normal PT which is about 12 seconds. I only found out I would have to take the drug for the rest of my life and test monthly during my exit interview from the hospital. I was rather cavalier in taking Coumadin for about six years post surgery.........and then I had my stroke.

I very much believe in diligent ACT but that does not mean I need to be a chemist or mathematician to successfully dose warfarin. I know my range is 2.5-3.5 and I use it all and even sometimes I go over or under my range by a tenth or two......and that's OK so long as it comes back in range on the next test. My years have taught me to follow the simple life rule....."KISS".
 
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