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

[Gkeraney]

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.

 

[pellicle]

to answer the question as asked it depends. I know people who take 10mg daily to maintain 2.5 and others who take 1.25mg daily.

if you actually want a quantitative methodology reach out in a PM and we can talk

 

[carolinemc]

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.

Good that you are making life changes, for it helps the heart and the body in losing the weight and having a regular exercise routine. When you do changes, INR will change with it till you system adjusts. When I start doing more exercise or movement, INR goes up. I have to watch it when taking Antibiotics, for some spikes the INR and some don't. Alcohol is something also.

 

[Timmay]

Everyone is different. And most of us are different during a year. At one time I was taking 14mg a day (98mg a week). I’m currently on 11mg a day.

I never use “weekly” dosage. IMHO the USA has that all wrong. Keep your daily dose the same (if possible).

My dosage can change for any number of reasons.

Diet
Supplements
Sick?
Meds
Exercise
Etc.

 

[Protimenow]

I agree with most of the above.

Test weekly.

Don't even THINK about weekly dose -- in theory, you can take the whole dose on one day, probably driving your INR way up, then it slowly drops, and you zap it again the next week -- it's best to shoot for the same dose every day. Again, weekly self testing - and minor adjustments if needed (Pellicle can help with this) is the best way to go.

And, as others have said, the dose needed varies from person to person, is affected by exercise, antibiotics, and other things that we may not even think about.

My required dosage over the past year or two has varied from 5 to 7.5. I just slightly adjust the dose to accommodate for changes in my body's reaction to warfarin, test weekly (or retest if a more major change is needed - like, perhaps, a test result below 2 and a slightly more major change in dosing than usual - retesting in three days), and you should be fine.

 

[Gkeraney]

Everyone is different. And most of us are different during a year. At one time I was taking 14mg a day (98mg a week). I’m currently on 11mg a day.

I never use “weekly” dosage. IMHO the USA has that all wrong. Keep your daily dose the same (if possible).

My dosage can change for any number of reasons.

Diet
Supplements
Sick?
Meds
Exercise
Etc.

Thank you. I communicated it on a weekly basis as that seemed to be what most people seem to say here. I don't think of it that way. I am a little encouraged you have had to take 14 a day. This 15+ and having an inr at 1.4 is very unusual I think.

 

[pellicle]

This 15+ and having an inr at 1.4 is very unusual I think.

it doesn't matter what is usual or unusual, it doesn't work like that. What matters is INR ... only INR. Just INR and you.

This is mentioned time and time again in both the advanced literature and here.

I recommend reading this as if you needed to pass a test on it (you do, the test is not having any issues). In particular this:

They circulate, bound to plasma proteins, to the liver where they are metabolised via separate pathways;the S-isomer is metabolised via cy-tochrome P450 (CYP) isoenzyme 2C9 whilst the R-isomer is metabolised by CYP3A4, CYP1A2 and CYP2C19.3 As mentioned above, there is a wide variation, up to 20-fold, in anti-coagulant response to a given dose of warfarin between different patients. This variation is due, in part at least, to genetic polymorphisms that affect both the pharmacodynamics of warfarin and its pharmacokinetics. Two genetic variants of CYP2C9 have been shown to reduce the metabolism of warfarin by between 30% and 80%, leading to an increased risk of bleeding.​

Or as I said above reach out and I'll help you work it out for you.

But do give up on the weekly dose thing, if you take your dose weekly you've got a problem. If you take your dose daily then for goodness sake just take the same dose daily and think in daily dose (like every other drug we use). Unless you're going to take it hourly ... then think in hourly dose. I'd take about 0.23mg hourly.

Best Wishes

 

[3mm]

I never use “weekly” dosage. IMHO the USA has that all wrong. Keep your daily dose the same (if possible).

Timmay - I don't understand this reference to the USA. Is there a place or an organization in the USA that talks in terms of a "weekly dosage"? Who or where? My coagulation clinic in Iowa (state in USA) and the Mayo Clinic in Minnesota (state in USA) both talked with me in terms of daily dosages. Do you think they were doing calculations as weekly dosages, which they then translated into daily dosages before they talked with me?

 

[pellicle]

Do you think they were doing calculations as weekly dosages, which they then translated into daily dosages before they talked with me?

based on my observance of this forum for about 12 years it seems almost everyone who uses that method is American.

I suspect that its changing, but its still around. In my case (Australian) nobody I've ever met in a clinical context has ever mentioned weekly dose ...

However I can see some sort of benefit to it as part of a broader method (which perhaps once it had).

1. its widely recognised that it takes approximately a week for a dose change to stably reflect in an INR
2. people don't like maths and so if you say average panic ensues
3. talking in a weekly dose presumes you'll then distribute that from a bowl in an even manner into your pill box (thus averaging {gags on average} it into a daily distribution).

that's as I see it

googling it and reading older posts will support that weekly does was quite common in the past.

Our search
https://www.valvereplacement.org/search/568093/?q="weekly+dose"&c[older_than]=2013-11-01&o=relevance

 

[Gail in Ca]

I take 7.5mg daily, except on Tues&Thurs I take 3.75mg.
This keeps me in range. About the only time I go out of range is if I’m sick and take acetaminophen or other medications.

 

[Timmay]

Timmay - I don't understand this reference to the USA. Is there a place or an organization in the USA that talks in terms of a "weekly dosage"? Who or where? My coagulation clinic in Iowa (state in USA) and the Mayo Clinic in Minnesota (state in USA) both talked with me in terms of daily dosages. Do you think they were doing calculations as weekly dosages, which they then translated into daily dosages before they talked with me?

That’s awesome news! My experience here in the USA (east coast, Maryland), although a very brief experience prior to moving to self management and doing everything on my own, was weekly dose. Nobody cares about keeping my daily dose the same. That “didn’t matter”.

Happy to see that things are changing!

Tim

 

[Superman]

based on my observance of this forum for about 12 years it seems almost everyone who uses that method is American.

I suspect that its changing, but its still around. In my case (Australian) nobody I've ever met in a clinical context has ever mentioned weekly dose ...

However I can see some sort of benefit to it as part of a broader method (which perhaps once it had).

1. its widely recognised that it takes approximately a week for a dose change to stably reflect in an INR
2. people don't like maths and so if you say average panic ensues
3. talking in a weekly dose presumes you'll then distribute that from a bowl in an even manner into your pill box (thus averaging {gags on average} it into a daily distribution).

that's as I see it

googling it and reading older posts will support that weekly does was quite common in the past.

Our search
https://www.valvereplacement.org/search/568093/?q="weekly+dose"&c[older_than]=2013-11-01&o=relevance

I think people hear “weekly dose” and over interpret what it means. I think of it in terms of if I need an adjustment, take a mg or so off this week to get in range. Which day I take that mg off isn’t that relevant, but if I’m over, it’ll probably be tomorrow.

For some reason people hear, “weekly dose” and think, “Those idiots must be taking 40 mg’s on Tuesday and nothing the rest of the week! Crazy people!” I assure you, nobody is doing that.

 

[pellicle]

For some reason people hear, “weekly dose” and think, “Those idiots must be taking 40 mg’s on Tuesday and nothing the rest of the week! Crazy people!” I assure you, nobody is doing that.

personally I don't think that anyone thinks that, but they may take 7mg and 5mg for instance.

Either way we've (you and I) had this discussion before and I think my above description is as probable as any.

 

[pellicle]

I don't understand this reference to the USA. Is there a place or an organization in the USA that talks in terms of a "weekly dosage"? Who or where?

https://health.ucsd.edu/for-health-...ulation-guidelines/warfarin/dose-adjustments/
https://bynder.uwhealth.org/m/5921479bfa74c27c/original/Warfarin-Initiation-Dosing-Protocol.pdf
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2386352/
https://www.ccjm.org/content/ccjom/70/4/361.full.pdf
https://pubmed.ncbi.nlm.nih.gov/11042238/

 

[ChuckM]

I take 7.5mg daily, except on Tues&Thurs I take 3.75mg.
This keeps me in range. About the only time I go out of range is if I’m sick and take acetaminophen or other medications.

Right there with you Gail, 7.5 MWF and 5.0 the other days. Has worked well for the past 2 years. I also didn't realize from the "how high have you seen" thread that the blood in the urine was a seemingly universal indicator of elevated levels. My diet remains pretty routine, and all it took was one time as another poster said of "partying too hard" and I've pretty much given up drinking all together.

 

[tom in MO]

Right there with you Gail, 7.5 MWF and 5.0 the other days. Has worked well for the past 2 years. I also didn't realize from the "how high have you seen" thread that the blood in the urine was a seemingly universal indicator of elevated levels. My diet remains pretty routine, and all it took was one time as another poster said of "partying too hard" and I've pretty much given up drinking all together.

I've had blood in my urine and an INR within range. I've had a high INR and no blood in my urine. There are several things more common than a high INR that can give you hematuria.

 

[ChuckM]

I've had blood in my urine and an INR within range. I've had a high INR and no blood in my urine. There are several things more common than a high INR that can give you hematuria.

Thanks doc! I've never had it happen until I began taking warfarin and my INR rose after a few days of partying, so I'm going to go with this time for me, my INR was high and I began passing blood in my urine. That's why I referenced the other post that apparently had the same issue.

 

[tom in MO]

Thanks doc! I've never had it happen until I began taking warfarin and my INR rose after a few days of partying, so I'm going to go with this time for me, my INR was high and I began passing blood in my urine. That's why I referenced the other post that apparently had the same issue.

My urologist says that blood in the urine is generally not caused by warfarin. If I see it, he wants to hear from me. There are other things that cause it, but being on warfarin makes it more visible. For example, a bladder stone may be giving you hematuria, which you will notice earlier because you're on warfarin (e.g. INR2=2x more blood in the urine.)

I "party" and don't have blood in my urine

 

[pellicle]

My urologist says that blood in the urine is generally not caused by warfarin.

that's hilarious! The metric given by GP's in days of yore to help you manage your warfarin isn't even a metric based on reality.

why am I so not surprised

 

[pellicle]

Hi

Thanks doc! I've never had it happen until I began taking warfarin and my INR rose after a few days of partying, so I'm going to go with this time for me, my INR was high and I began passing blood in my urine. That's why I referenced the other post that apparently had the same issue.

its entirely possible that it was INR related, but we can't be 100% sure of this

elevated INR post drinking is not only well documented it has a basis in how the whole thing works. Simplification = "the body is busy getting rid of the worse toxin" and so the usual disposal system is pre-occupied.

Processing out warfarin will eventually return to normal when your BAC goes down. I typically see 2 days of elevation trending towards normal. Some people (including me) knock my days warfarin down by 25% preferably before hitting the sauce, but after works too.

YMMV