INR going low with increased warfarin, advice needed!

[katiewintle]

Hi all need you advice about my warfarin/INR
My range is 3-4, ideally 3.5.
5/10/15 - 4.8, 7/8mg alternate days
12/10/15 - 3.1, 7/8mg alternate days
28/10/15 - 2.9, 7mg Mon & Thurs 8mg other days
6/11/15 - 2.8, 8mg daily
13/11/15 - 2.9, 9mg Mon & Fri, 8mg other days
20/11/15 - 2.7, 8/9mg alternate days
27/11/15 - 2.6, 10mg Mon & Fri, 9mg other days.
Done 3 tests on my own machine this week with readings of 3.6 (tues), 3.7 (thurs) and 3.3 (today) which was done after my appt at clinic.
I have not changed what I eat or drink, no changes in medication either. Any ideas?

 

[Superman]

First off - I've never seen 3 - 4 as an ideal range. 2.5 - 3.5 seems to be the upper end (from my experience) for those with St. Jude or other non-On-X valves. You've been above 2.5 the entire time - so I wouldn't worry too much.

Assuming you are correct about dietary consistency, my only real questions would be regarding time of day for both testing and taking your med. Are you sure you haven't missed a dose? When you go to the get tested, is it at the same time of day? Do you take your med in the morning or evening? If in the evening, are you punctual (are there nights where you're out and about, and realize at 11 pm, you haven't taken it yet for example).

Prior to the October 5th test, did you have a long period of consistency, or is fluctuation pretty normal for you?

 

[katiewintle]

I take my warfarin around 6pm each evening and haven't missed any doses. I usually get tested on a Friday afternoon. I have been taking folic acid since 1/8/15 as my husband and I want to start a family under the close guidance of my cardiologist. I had my mitral valve replaced with a mechanical valve in August 2009 and was told my INR range would be 3-4. Over the past year my INR has been up and down but my general dosage has been either 7/8mg alternate days or 8mg everyday.

 

[Superman]

Mitral may be the reason for the higher range then. In addition to adding the folic acid, were you on birth control before and since stopped taking it? Hormonal changes can take a little while to work themselves out.

 

[katiewintle]

I am on cerezette which is the mini pill. Have been on this continually for the past 8 years. I had a stress echo test on Wednesday to find out how my heart copes under pressure. Get the results in a few weeks time. If we are able to progress with trying for a baby I will then stop my pill.

 

[katiewintle]

I am on a birth control called Cerezette, been on it for over 8 years now without any breaks (apart from when I had my valve replaced which was 6 years ago). I will be stopping this soon, as soon as I get the go ahead from my cardiologist.

 

[Superman]

http://www.ncbi.nlm.nih.gov/pubmed/20206792

Here's a link to a study on folic acid supplementation and warfarin. It doesn't appear a significant link was found. This study was for those that were deficient to start. It doesn't appear you were deficient, but rather boosting in anticipation of family planning. Maybe the response is different in somebody with normal levels looking to go higher.

Sometimes the change we made doesn't seem like a change at all, but our body responds differently. I learned the hard way that warfarin and cranberry juice don't react well in my system. Before, I would have said trading daily orange juice or apple juice for daily cranberry juice is not a significant dietary change. I now know that cranberry juice sends my INR through the roof (blood in urine and an INR of nearly 10). I stay away from the stuff now.

I guess you'll have to consider all of your changes whether you currently deem them significant or not, to identify the culprit.

Then again, sometimes as we age, our metabolism just changes and we have to adapt to a new normal.

 

[katiewintle]

Do you think vitamin C has an effect on INR? Round this time of year I like to eat satsumas. I have 2 at a time probably once or twice a week. I also like to drink Robinsons Apple and Blankcurrant squash which I think contains vitamin C (unsure of how much).

 

[pellicle]

Hi

Hi all need you advice about my warfarin/INR
My range is 3-4, ideally 3.5.

I see you have a mitral valve. So while I understand that for a Mitral the range is often given as 3.5 research is emerging to demonstrate that that's higher than needed. So what I'm saying is that you are OK where you are, so no need for anxiety ... so lets now look at getting you back to where you want to be (and you can discuss the lower ranges if you are interested later)

5/10/15 - 4.8, 7/8mg alternate days
12/10/15 - 3.1, 7/8mg alternate days
28/10/15 - 2.9, 7mg Mon & Thurs 8mg other days
6/11/15 - 2.8, 8mg daily
13/11/15 - 2.9, 9mg Mon & Fri, 8mg other days
20/11/15 - 2.7, 8/9mg alternate days
27/11/15 - 2.6, 10mg Mon & Fri, 9mg other days.

I see that on the 5th of Oct a value of 4.8, this is a little higher than I'd be targeting and then it started to return to the ~3 range. What had it been before this period?

I have not changed what I eat or drink, no changes in medication either. Any ideas?

I'm going to go with it having been lower than 4.8 before the 5th of Oct and so its actually cycling low from being high earlier. Please let me know if my assumptions are wrong. I find that with all homeostatic things some cycling around equilibrium is common, probably natural. I guess its observations like this that drove some people to develop the (unsupported nonsense) theory of biorhythms.

I'm going to go out on a limb and say you stick with 9mg daily for a week, test again and see where it goes. I too get these intermittent cycles of INR which sometimes I adress with changes (small changes) and other times I don't. Usually its a bit like that lamb and comes home in a while. For instance here is my 2014 data and you can see some interesting things in there.

At the beginning of the year my INR was trending low and I made some dose adjustments. I kept it above 2 and while my daily dose (expressed in mg / day but taken consistently for the week) altered between 7 and 8.5mg there was a bit of a rollercoaster in the middle.

It is my view that this is not in itself dangerous, it just is. The point of the matter is to keep it between the range as much as possible (and occasional stray out is very unlikely to be harmful).

You may be just in the midst of such a cycle (I could find no clear cause for mine) so my view is (as always) keep calm, monitor with a frequency that gives you a sense of being informed and keep a steady hand on the tiller (IE make adjustments small). Like navigation at sea, its the destination thats important and if headwinds or currents take us of our course we adjust as needed. We don't really need to know why the bow is pointed too far port or starboard, just how to adjust to keep on course without skewing all over the shop.

Please post back with your next weeks readings and lets look again.

Best Wishes

 

[pellicle]

Do you think vitamin C has an effect on INR? Round this time of year I like to eat satsumas. I have 2 at a time probably once or twice a week. I also like to drink Robinsons Apple and Blankcurrant squash which I think contains vitamin C (unsure of how much).

Just watch out for large doses of Grapefruit and some species of mandarin. They seem to work to increase INR.

https://en.wikipedia.org/wiki/Grapefruit–drug_interactions

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