Hi I don't think that's uncommon. I've been on warfarin for 7 years and my INR will be stable for a good long while and then it periodically gets wonky and then the next thing you know my body just needs a different dosage going forward.

I'm in the same sort of deal right now. I've been on 5.5mg for a while now, but suddenly that keeps dropping me into the 1.7-1.9 range. We've been slowly upping my dose a few days a week and it seems like three days at 6mg are keeping me closer to 2.5 or so.

I'll also note that I used to be a 6mg a day taker. But I went through a period where that was putting me about 3 on a regular basis so we dropped it to 5.5 daily, which was fine for a good year and a half or so. But, now it's going the other direction.

This is why we test warfarin on a regular basis. Sometimes, you will need a change ... for me, I've never really known *why* my dose needs changing, just that it periodically does.

Yeah over the last several years, I was on 11-12mgs for quite a while, like for over a year, then it went up to 13mgs at some point. It was up to 15mgs a while and now I've been at 14 mgs a day for almost a year.

It happens. I stopped trying to figure it out a long time ago because while I can account for dietary changes or activity changes or medication interaction changes, I can't account for any other nuances that may be going on in my body that may or may not affect my INR. Fortunately, my current doctor and his staff are not worried about these changes. But I used to see another doctor years ago who's staff almost seemed to accuse me of screwing something up because my INR changed. I thought, hey not for me to figure out- adjust my dosage and get over it.

Thanks for the replies. I guess I am just frustrated as I try and keep pretty regular with what I eat and if anything, am eating less vitamin k foods. Do any of you notice the heat of summer affecting your INR? And, speaking of going up, my warfain just went up from $16.98 for 195 tabs to $58.26!

I never noticed the heat to affect my INR, but it sure affects my chest. If I overheat, I get really bad chest pains. It took me a while to get my INR in range (I was around 1.3-1.4 for about 6 weeks), and I realized that the more I worried about it, the harder it was to just calm down about it. I don't think that worrying about INR would be affected by this, but it just seemed like the less I worried about it, the better it started to get.

Same for me. When I first started warfarin, it took months to get up to at least 2. I was always so stressed out about. It did seem that once I just figured out how to relax about it, things started to stabilize. Why, not sure.

I too haven't noticed heat affecting things. I think our bodies change over time and that may have something to do with it.

I have been a Phlebotomist for 25 years now, what you're experiencing, I have witnessed for several years. It happens. Seen it so many times. With so many different patients. All different times of the year. That's why the MD's monitor the level, so it stays in the therapeutic range. Because it can and will "go out of whack".
Currently on Xaralto.