False Increases in INRs - QC doesn't catch - WARNING

[tobagotwo]

When you find a relationship like this, it's important to get it on the books. The FDA has adverse event reporting for all types of things, and what they get from patients helps decide if the makers of flavonols need to display a warning against using with warfarin, or if the next person (who hasn't read your post) might also risk a stroke.

Here's some info on the program: http://www.fda.gov/Drugs/GuidanceCo...n/Surveillance/AdverseDrugEffects/default.htm

Here's the reporting page (online or hard copy reporting): http://www.fda.gov/Safety/MedWatch/HowToReport/ucm053074.htm

You could report it as a Quercetin issue. They won't do anything based on just your report, so don't feel guilty. If others find it true, they will report it as well, and then it will become important. If no one reports it, the FDA is not going to know about it. You could also report it as the meters (medical devices), because that may wind up having them display a caution that some drugs may fool their meters. A stroke is a very big deal, even if you walk away from it okay in the end.

One caution: it's best to not allow the FDA to put your name to it, as that may cause manufacturers to call you and try to prove that you don't know what you're talking about. I reported my first valve, but when the form asked, I didn't allow the company to have my name. I believe the FDA did require it for themselves, but they never contacted me. I know some members here have said that they were bothered by manufacturers who kept questioning them to find out how they could invalidate the issue. If enough people see the link and report it, it will bear fruit.

Be well,

 

[Protimenow]

Hey, Bob. Thanks for the info. The issue may actually go deeper, with InRatio claiming +/- 30% accuracy from 2.0-4.5. this means that a 2.0 could actually be a clinical 1.4.

I am getting tested tomorrow by a Hemochron, which uses a different method for determining INR than that used by InRatio. If I had the financial resources, I'd get ProTime cuvettes so that I can use my ProTime meter to test my INR (and compare it to the InRatio to see if this is a meter-specific issue, or perhaps even a non-issue), and would also like to test on the CoaguChek XS and on a new meter that, for some odd reason is still under the radar but appears to perhaps be the MOST accurate meter available.

I'm not sure that I'll report the Quercetin issue until I do my testing tomorrow and see if the InRatio and the Hemochron are apart as much as last week's blood draw and the InRatio were.

IF THEY ARE, this is an important Public Health issue that people should be made aware of, and a possible important issue relevant to the method used by this particular meter.

But, again, thanks for the link to report this.

 

[tobagotwo]

Flavonoids do not hang around - they are water-based. If you've already stopped the Quercetin for a couple of days, it's out of your system. So your timing is probably good.

Frustrating when you can't trust things that you need to trust! Great catch, and great association of causative factors.

Best wishes,

 

[sarahsunshine]

I wish I lived nearby and I'd lend you our Coagucheck meter! We get free strips (covered by insurance), but even so it would be worth the $10 each to know if flavinoids are tested the same way on the coagucheck as the INRation. Does anyone else live nearby?

 

[Protimenow]

I didn't stop the Quercetin so that I can see if the Hemochron has a similar bias (I would be surprised if it does). In the morning, I'll test my INR on the InRatio, then go to the clinic for the hemochron test.

 

[sarahsunshine]

Can you take your INRatio to the clinic and do it at the same time pretty much exactly or are you pretty sure that it's close enough? Whenever we compare we use the same venous blood. Just curious.

 

[Protimenow]

Sarah:

The Coaguchek XS and InRatio meters are ONLY designed to use capillary blood. This is why they want you to use the FIRST drop. There are factors in the first drop - clotting factors just below the surface of the skin - that the meters factor in when calculating your INR. Venous blood doesn't have the same levels of these factors, and a venous blood reading using either of these meters will NOT reflect the actual values that the meters are designed to report.

The ProTime meters are designed for the second and later drops of blood -- they can be used to test venous blood.

(I have a ProTime, but no cuvettes. I'm thinking, when I've got the funds, of buying some more cuvettes or getting a newer meter that measures actual clotting).

As far as testing before I go to the clinic -- I will run a test using one or both InRatio meters - probably less than 30-45 minutes from the timing of the blood draw at the clinic. I don't expect anything to change between the time I test at home, and the time I'm tested at the clinic.

Unless I get injected with Lovenox while I'm on my way to the clinic, I can't imagine anything that can significantly alter my blood in those few minutes.

 

[Protimenow]

I wish I lived nearby and I'd lend you our Coagucheck meter! We get free strips (covered by insurance), but even so it would be worth the $10 each to know if flavinoids are tested the same way on the coagucheck as the INRation. Does anyone else live nearby?

Sarah:

Although it would be great if I could be tested using a CoaguChek XS (I'm in the San Fernando Valley, in case there's anyone nearby who wants to swap tests), I can maybe do something slightly better.

I have hundreds of Quercetin pills. I can certainly spare a LOT of them. If someone with a meter would like to take Quercetin for a few days - testing before starting to take it, and then after they're sure it's in their system, then reporting the result, I would be happy to send off a dozen or two (or more). Just send me a private message (my private message mailbox may fill up, but I'll keep trying to empty it so that your request comes through). (Also - while I'm feeling generous, I have a lifetime supply of 21 gauge lancets - I can even send a box of 200 to the first few who ask).

Just let me know.

 

[Protimenow]

I'm still trying to confirm the relationship between a material (Quercetin) and an increase in reported INR on at least one of the meters. My experience this morning continues to point in that direction.

I took my INR using my meter this morning, and got a reported 3.7. An hour later, the clinic's Hemochron reported a 3.2. This difference in values was pretty consistent with previous differences between the two meters. (The Hemochron uses a different method to determine clotting than the InRatio or CoaguChek meters. I don't have a CoaguChek XS, so I haven't been able to see what this meter would be reporting as my INR).

When I can, I may get some Cuvettes for my old Protime 3, or a new meter that few people know about, and test with these machines. My guess is that the ProTime 3 will be consistent with the lab and with the Hemochron's results.

 

[mecretired]

I tested my inr on Monday am using my Coaguchek XS and got 3.7--I went immediately to the lab for a vein draw (which they send by courier to Lenexa KS and I get a result the next day) Anyway the lab got 3.6. So I'm pretty pleased. I still plan to get a lab inr periodically and even compare the two periodically--especially if I start any new meds, etc. So glad you're doing OK Protimenow. I wish everyone had a "team" to help us along this warfarin path--most of us are fortunate if we have 1 professional who actually knows what they are doing.

 

[Protimenow]

It's good to occasionally compare the meter readings with lab results. I wasn't able to get this comparison until three weeks ago -- and I was surprised by how different the two were.

The 'clinic' talks about 'calibrating' the meters -- but they can't really be 'calibrated.' It's good to be able to compare their readings to the lab results. I'm suspicious of certain things that may fool the meters into erroneously high (and maybe erroneously low) readings, and it's important to find out any foods or medications that may cause incorrect results. (I should have a better idea on Friday if a particular pill caused my meter to report higher than accurate results).

 

[RobThatsMe]

PT,

Sorry to hear of your recent issue. I hope you do have a full recovery from it.

I do have to ask though, you have posted before that you look for, and purchase, older, and in some cases, expiration dated test strips.
Were you using these older test strips for you recent tests? I think that this should be noted in fairness to all home testers for this thread.

Thanks,
Rob

 

[Cris N]

Having learned from the school of hard knocks when an herbal was recommended to me I ALWAYS check new medications, whether prescribed or OTC for warfarin interactions. That way I am at least informed a prepared for changes.

 

[Protimenow]

Rob:

In earlier posts I indicated that the strips I used were current, fresh strips. I haven't used an expired strip for probably a year or sol (I was also told that, for InRatio and possiblyInRatio2, strips are good for up to one year after the expiration date). The only reason that I was looking or expired strips was to save money because I wasn't able to afford new strips and was running out of my still current ones.

 

[RobThatsMe]

Rob:

In earlier posts I indicated that the strips I used were current, fresh strips. I haven't used an expired strip for probably a year or sol (I was also told that, for InRatio and possiblyInRatio2, strips are good for up to one year after the expiration date). The only reason that I was looking or expired strips was to save money because I wasn't able to afford new strips and was running out of my still current ones.

Thanks for the update PT! Based on this, I will most likely target the higher end of my range. My range is 2.5 - 3.5, so I think I will shoot for 3.0 - 3.5 from here on out.

I'm with you an saving money on test strips. I really think they are way over priced, and as you noted, it's all insurance related.
Now wonder our medical costs are so high these days. I used to purchase ProTime testers 25 for $280. I was floored when Alere started charging almost $400 for a box of 12. What a rip-off!

Rob

 

[Protimenow]

Rob:

You can get ProTime testers from a real dealer on eBay for about $145. This is still a lot more than InRatio and CoaguChek XS strips, but a lot better than $280.

I'm planning on / hoping to go back to the ProTime tester -- a bit more of a hassle to use, and the strips have to be refrigerated - but I suspect that they may be less prone to uncaught errors than some of the other meters. (In addition to this, the meters are from the company that sells the Hemochron, which is used in hospitals - and even in operating rooms - to determine various blood factors).

 

[Protimenow]

I've been rethinking this just a bit. In retrospect -- without blood draws to compare my InRatio (and InRatio2) to, I was assuming that the blood draw and InRatio results were roughly the same. I blamed the spike on the effects of Quercetin, somehow fooling the results reported by the meter.

Now, after many more tests with the InRatio -- and a handful of actual lab blood draws -- it appears that the InRatio is ALWAYS .4-.8 (or so) higher than the lab. Quercetin may not have been a factor - it may have just been a characteristic of the meter (and something about my blood?).

To complicate things just a bit, I'm also testing with a ProTime and a ProTime 3 meter. The only time I had this compared to a lab, the two were almost exact. Now, it appears that the ProTime tester(s) is LOW, and the InRatio is high. It's possible that an AVERAGE of the two meters may be very close to the lab. (Yesterday, the InRatio 2 said 4.1, the ProTime said 3.1 -- which puts me at the high end of my range. I'll cut back slightly on my dosing.).

I'm going to contact the makers of the ProTime and ask them about possible calibration (I don't think these meters should be - or could be - calibrated, but they DO have standard test solutions for determining accuracy) - and get their feedback on why the ProTime results should be .5 or so lower than the lab results.

As regards the title of this thread -- it's possible that Quercetin may have had a minor effect on the results - perhaps .2 or .3, and that the meter will always report higher than the lab. I'm not going to fear Quercetin any longer - I'll just aim at keeping my INR - as reported by the InRatio, between 3.0 and 4.0. This should assure that I'm in range.