Highest INR you have heard of or experienced?

A routine blood check (2009) revealed mine had skyrocketed to
Protime = 100
INR = 11.2

My primary care physician immediately called me and told me to go directly to the emergency room. I was quickly registered and got my room, and when the nurse came in I had told her the values that I had. She said I had to be wrong because the INR can't go higher than 10. I told her differently, and they quickly rechecked it and it was 12.5. Nobody Knows the reason why it jumped so high, I can only imagine what they might have thought I did to myself, but I am still perplexed. They got it regulated and I was out of the hospital in about 3 days after extensive procedures and testing. What is the highest you have experienced?

WOW! Another good reason to check INR every week or two.......although at 12.5 I would think you could see it in your urine..... bright red or red-brown color. I've had only a few a little over 5 in all my years on warfarin........and I think that was due to "hard-partying".

thomas999 said:

A routine blood check (2009) revealed mine had skyrocketed to
Protime = 100
INR = 11.2

My primary care physician immediately called me and told me to go directly to the emergency room. I was quickly registered and got my room, and when the nurse came in I had told her the values that I had. She said I had to be wrong because the INR can't go higher than 10. I told her differently, and they quickly rechecked it and it was 12.5. Nobody Knows the reason why it jumped so high, I can only imagine what they might have thought I did to myself, but I am still perplexed. They got it regulated and I was out of the hospital in about 3 days after extensive procedures and testing. What is the highest you have experienced?

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Stress and illness can affect the INR. And also if you are taking antibiotics or other meds. Seems this is a problem with hospital staff all over the world and this happens a lot for diabetics also. They cannot believe the results and call the patients telling untruth, but we know better than they.

This one isn't particularly easy to answer.

It's not easy because lab results aren't always accurate or reliable.

I had one doctor tell me that my INR was 7.

I had some clinics tell me that my INR was also 7 -- but I tested on my meters the same day, and saw that my INR was within range.

One doctor told me that my INR, and that of another patient, was 5.1.

Testing by two other labs said 3.5 and 3.6, and my meter had an even lower number. Clearly, the results of the lab reporting 5.1 were wrong.

I was told about some anticoagulation clinics using a second meter (Coag-Sense) to test all INRs above 4.0, as reported by the CoaguChek XS, because above 3.0 or so, the XS results tend to be a bit higher than actual INR.

My advice - when you have an INR reported to be more than 4.5 or so, get it retested before you make any dosing changes. It may be a lab error.

Highest I have had so far is a 4.9. I check weekly so this was really odd. I took a day off warfarin and rechecked and was at 3.9. Home testing. The 4.9 was likely correct. It worried me for sure but later reading items here from pellicle has me thinking its fine to get up to 4 for sure, though it's not that you want to stay there. In general I had been aiming a bit too low, toward upper two's.

Upon release from the hospital after valve surgery, and before I self tested, I was put on oral amiodarone. Amiodarone is used to help stabilize heart rhythm for afib patients and I had a couple of bouts of afib following my surgery. Within a few days, my INR shot from 3.1 to 9.7.
Of course I was very concerned. The coumadin clinic asked if I had any vitamin k at home. I just had vitamin k2. They had me take a megadose of k2, after doing some calculations. They also called in a prescription for one 5mg tablet of vitamin k, of which I was supposed to take half.

The vitamin k worked very well. In fact, so well that the next day I tested at INR 1.6 and now it was an issue being below range. Things soon normalized.

It turns out that amiodarone is well known to cause INR to go through the roof. Depending on the dosage of amiodarone, it can have the same impact as doubling your warfarin dosage. There were a number of people who should have alerted me to this and should have been watching my INR more closely, including the prescribing nurse, the hospital pharmacist and the coumadin clinic. To get my INR back in range, my warfarin dosage had to be droppep to about half of what I was taking previously. Once I was off the amiodarone, my dosage for warfarin returned to what it was pre-amiodarone.

I asked the clinic at what point I need to head to the emergency room. They said that INR of 11 was the threshold to seek ER attention. That is probably somewhat of a subjective call.

Bacterial endocarditis was my culprit.
My INR was 6.7 when I noticed blood in my urine. I had already taken my warfarin when later I noticed the blood. A Dr on call said stop warfarin the next day and test the day after that. So, I did that and couldn’t get a reading on my Coaguchek xs. The error said my INR was too high to read! I had a horrific headache the night before this test try. I went to urgent care, my INR was 8. I had a brain bleed. They had me taken to the hospital where it was 9.3. I was given 2 maybe 3, shots of vit K. I was going into DIC. The shots worked. The ER doc thought I had arteritis and wanted me to go to Stanford. I agreed immediately. However, by the time it took to get that transfer going my labs came back showing I had bacterial endocarditis from staph. Lugdunensis. I wanted Stanford anyway so I was sent there and treated. My INR has never been that high or even close since then!

Protimenow said:

This one isn't particularly easy to answer.

It's not easy because lab results aren't always accurate or reliable.

I had one doctor tell me that my INR was 7.

I had some clinics tell me that my INR was also 7 -- but I tested on my meters the same day, and saw that my INR was within range.

One doctor told me that my INR, and that of another patient, was 5.1.

Testing by two other labs said 3.5 and 3.6, and my meter had an even lower number. Clearly, the results of the lab reporting 5.1 were wrong.

I was told about some anticoagulation clinics using a second meter (Coag-Sense) to test all INRs above 4.0, as reported by the CoaguChek XS, because above 3.0 or so, the XS results tend to be a bit higher than actual INR.

My advice - when you have an INR reported to be more than 4.5 or so, get it retested before you make any dosing changes. It may be a lab error.

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I trust my lab due to the fact I am there from the finger prick to the results at the lab. I have had no issues with that.

What does the lab have to do with a finger prick? Labs require more blood than you can get from a finger prick -- you can't even transport a drop of blood to the lab before it starts to coagulate.

If it's just a finger prick, they must be using a meter. Or are they drawing blood at the same time as they do a finger prick with a meter and comparing the results?

it depends on the lab, but anything over 9 is usually declared "uncoaguable" AFAIK. I don't think I have measured anything over 4 on me

thomas999 said:

Knows the reason why it jumped so high

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have you been drinking grapefruit juice or eating Spanish mandarins?

https://cjeastwd.blogspot.com/2021/05/grapefruit-and-warfarin.html
citation about furanocoumarins contained within that.

Salmon Mousse can be deadly too

Brown urine alerted me to an issue some years ago. I was over 10 INR. I wasn’t in a great place in life. I was being monitored by the lab as home monitoring wasn’t a thing yet. So a combination of a messed up diet (I was losing weight, but not in a healthy way) and lack of monitoring led to the high side issue. Got it fixed up pretty quick when the issue showed up. Kind of snapped me out of my funk too. At that time I didn’t have this place either, so I was kind of on an island with my own pity party.

Chuck C said:

Upon release from the hospital after valve surgery, and before I self tested, I was put on oral amiodarone. Amiodarone is used to help stabilize heart rhythm for afib patients and I had a couple of bouts of afib following my surgery. Within a few days, my INR shot from 3.1 to 9.7.
Of course I was very concerned. The coumadin clinic asked if I had any vitamin k at home. I just had vitamin k2. They had me take a megadose of k2, after doing some calculations. They also called in a prescription for one 5mg tablet of vitamin k, of which I was supposed to take half.

The vitamin k worked very well. In fact, so well that the next day I tested at INR 1.6 and now it was an issue being below range. Things soon normalized.

It turns out that amiodarone is well known to cause INR to go through the roof. Depending on the dosage of amiodarone, it can have the same impact as doubling your warfarin dosage. There were a number of people who should have alerted me to this and should have been watching my INR more closely, including the prescribing nurse, the hospital pharmacist and the coumadin clinic. To get my INR back in range, my warfarin dosage had to be droppep to about half of what I was taking previously. Once I was off the amiodarone, my dosage for warfarin returned to what it was pre-amiodarone.

I asked the clinic at what point I need to head to the emergency room. They said that INR of 11 was the threshold to seek ER attention. That is probably somewhat of a subjective call.

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My experience was similar to Chuck. I had some afib in the hospital after AVR and was put on oral amiodarone. After discharge from hospital, I had appointment with cardiologist who sent me to lab for INR check which registered 1.5. My first coumadin clinic appointment two days later measured INR as 2.3. So my second clinic appointment was a week later on a Friday where INR was 7.0. Fortunately, I had no symptoms or signs of an elevated INR at the time. I was told to skip my warfarin doses for two days and take a half dose Sunday and return to clinic on Monday. I was not offered a vitamin k prescription, but I had turnip greens saved in my freezer from my gardening efforts the previous autumn. So I ate a lot of turnip greens and broccoli over that weekend. My INR was back down to 2.2 on Monday.

My warfarin dose was reduced to about 2/3 of the initial dose, and my amiodarone dose was cut in half that week and then stopped altogether 4 weeks later. My understanding is that the amiodarone stays in your system from weeks to months where this can vary substantially for different people. As such, I think there can be a ramp up effect upon starting it, and an extended ramp down when stopping it. So my warfarin dose gradually increased over time as the amiodarone factor subsided.

I observed mild petechiae primarily on my torso that I speculate might have been prompted by the high INR episode albeit with a delayed effect. Although they are not really a concern, I did not expect these little dots to persist indefinitely as they are still visible years later.

Aquila said:

my amiodarone dose was cut in half

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That stuff messes with INR big time

Aquila said:

My understanding is that the amiodarone stays in your system from weeks to months where this can vary substantially for different people.

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This is true. amiodarone has a very long half life and can still be in your system months later. This is another reason why I am glad that I started self testing about one week out of the hospital. As my amiodarone dose was tapered down, I had to take larger doses of warfarin to stay in range. This continued for at least a month after going off of it.

For those on amiodarone, super important to test often, not only after initial administration, but also as the dose is tapered down and for some time after it is discontinued. Just as one needs to reduce warfarin after being put on amiodarone, as your system clears the amiodarone, you will almost certainly need to increase warfarin dose to stay in range. It is a time when a person should test INR at least once per week, in my view.

I had covid in April and got prescribed antiviral meds. Due to contraindications for Paxlovid they gave me Lagevrio. I had my INR checked two weeks later and it was 4.7. Presumably it was much higher while I was on the antivirals and couldn't get an INR done because I was contagious with covid. My GP freaked out and wanted me to change my dose, I suggested skipping a dose and rechecking in a week. Sure enough I was back in range.

Elcarim said:

I had covid in April and got prescribed antiviral meds. Due to contraindications for Paxlovid they gave me Lagevrio. I had my INR checked two weeks later and it was 4.7. Presumably it was much higher while I was on the antivirals and couldn't get an INR done because I was contagious with covid. My GP freaked out and wanted me to change my dose, I suggested skipping a dose and rechecking in a week. Sure enough I was back in range.

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Another argument for self-testing! You can do it at home (or wherever you are), not needing to see anybody else.

Years ago, I was able to get in touch with the CEO of Coagusense, makers of the Coag-Sense meter. He told me that there are some places (hospitals? clinics?) that switch from the CoaguChek meter to the Coag-Sense to validate results if the CoaguChek results are 4.0 or above.

I don't know who, or where, these places that use the Coag-Sense to validate high numbers, but since they changed management a few years ago, my confidence in the company and their test results has dropped so much that I haven't bought any more strips, and haven't tested with a Coag-Sense meter for well over a year. (And without any recent strips, I don't think I WILL, either).

LondonAndy said:

Another argument for self-testing!

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personally I don't even see why any arguments can be made against it. Ignorance is only bliss if due to ignorance you die; then its all quiet.

The only argument against it is the inability of the person to self test. These can be issues of cognition, coordination, etc. Other than that, I fully agree that anyone on warfarin SHOULD (MUST?) self test, and if they're able to, self manage. The medical (including nursing and pharmacists) community is mostly ignorant in anticoagulation management. In many cases, they may not even be savvy enough to even be trusted. (Yeah, I'm maligning them, but many - if not most, deserve it.)

Where I get my INR done if it comes up over 4.0 they have to do it again. I have had this done several times and it has always been the same or very close on the second test. I actually asked last time this happened if the second test is ever magically in range and the nurse said that sometimes with elderly patients there can be a big discrepancy between one hand and the other.