Affect of Lovenox shots on INR

[Sherryl]

It's been so long since I posted, perhaps 5 or so years, that I can't remember my registered name. I think it's SusieQ. Never mind the details. I wish I would have taken the time to post my question pre-procedure. However, due to a scheduled breast biopsy, I was told I had to stop coumadin for 7 days prior & 2 days post. My cardiologist thought this was too long, but radiologist said that was her requirement, so we went with her regime. I gave myself Lovenox shots for those days.

Now I've been back on coumadin for 7 days. My INR this morning was 2.1. My range for a mechanical aortic valve is 2-5 - 3.5. To maintain that range, I usually take 12 mg 5-6 days a week & 10 the other day or two. The morning of the evening I began taking the Lovenox shots, my INR was 5.1. I had begun taking krill, in addition to the Omega 3s I'd been on for 4 years based on recommendation from cardiologist. Don't know if that was the cause or not. Now my INR is 2.1 as previously stated.

Do Lovenox shots have residual affects? I self-test & because of the ease with which the blood flowed onto the test strip this morning, I felt my INR would have been high. However, the opposite occurred. Is this normal?

Another question. I purchased my own InRatio machine in 2007 to take on a long trip. Because BCBS wouldn't reimburse me, after I returned, I contined to go to Coumadin Clinic. Basically between July of 2007 and October 2011, I did not use my machine. When I ordered the strips from Alere, I didn't want Medicare to have to pay for another machine so I've continued using the one I purchased. I've changed the batteries to make sure it is testing accurately. Is there a life span for these machines? Could that be the reason for the ups & downs in my INR?

Sorry for the length of this post, but I had several questions. I'd appreciate any feedback you could give. Thanks.

 

[sarahsunshine]

Lovenox (or Enoxaparin) works on a different place in the coagulation chain than warfarin. INR measures do not measure the effects of Lovenox.

http://en.wikipedia.org/wiki/Enoxaparin_sodium

 

[RobThatsMe]

I have had to bridge with Lovenox twice, and I have been home testing for the last 12 years.

The rule that I used with the lab was that I would continue the lovenox shots while starting back on my Coumadin dose. Once my INR tested at 2.3 I could stop the lovenox shots, continue my Coumadin dosing, and then maintain my home testing every 3 days until I reached my theraputic range between 2.5 and 3.5

Keep in mind that it does take at least 7 days for the Coumadin to build back up in your body after you have whined yourself off of it.
Also, after that it does take a while for it to settle into range.


Rob

 

[Sarah_Louise]

I take tinzaparin heparin daily as my long trm anti-coglant, it has no effect on INR & isn't tested via INR, it's tested by a Factor 10 venous blood test, I have mine done every 6 weeks as like i said im on it long term, but short term use doesn't require any testing
http://en.wikipedia.org/wiki/Anti-factorXa#Anti-factor_Xa_activity
Love Sarah xxx

 

[newmitral]

Hello Sherryl,

I self-test & because of the ease with which the blood flowed onto the test strip this morning, I felt my INR would have been high. However, the opposite occurred. Is this normal? ​

I also have the Inratio2 machine and get the test strips directly from Alere. Although I have only been self-testing INR since about November 2011, I have noticed that there does not seem to be any correlation with how freely blood flows and the resulting INR reading of the test. Quite often it seems to me that my blood flows very freely, and I expect the test to show a high INR, but the result is low. Similarly, there are times when the INR reading is high and it doesn't seem to me that the flow would indicate that.

Do Lovenox shots have residual affects?​

I have had to bridge with Lovenox twice since I started taking warfarin in May of 2011. Like you, I also take a fairly high dose (12.5/day) to maintain the 2.5-3.5 target INR range. After my most recent surgery this January, it took 3 weeks for my INR to get back into range taking my regular dose. I helped it a bit in the second week by taking a bit over my normal dose (13.5 to 14 mg) for a few days.
A full 7 days of taking warfarin after the surgery, my INR was only up to 1.2 , and I was continuing to take the Lovenox shots because the INR was remaining so low. Two weeks of taking warfarin after my surgery, my INR was still only up to 2.1, at which time I stopped the Lovenox since I was close enough and with the ON-X valve I felt I could be a bit loose with the target range lower end. It was not until three weeks of being back on my regular dose of warfarin that my INR got back into range at 2.5 on the test at week 3.

Now, I can't say whether my experience is typical or not, but in my case returning to "warfarin stability" after bridging seems to take a long time.
I should note that it took an equally long time to get me in range when I first went onto warfarin after the OHS to replace my valve. The doctors had me go for several extra INR tests at the lab and take Lovenox shots then as well, until my INR got above 2.0 on the initial startup with warfarin.

Is there a life span for these machines? Could that be the reason for the ups & downs in my INR?​

The meters have a built-in self-test and calibration, so I would doubt that the home test is inaccurate just because the meter is old. It should give you an error indication if it failed its calibration/self test.
A couple of times, I have had my INR jump from 2.5 to 4.5 in one week with absolutely no change in my diet or routine. This is using the same meter and the same batch of test strips. I think ups and downs of INR are just part of life with warfarin/coumadin.

When I get to 4.5 or higher, my doctor usually has me hold the dose for a day or two. So, your stopping 7 days before surgery with an INR of 5.1 was probably a good thing. The doctors had me stop the warfarin 4 days before each of the two surgeries I had, and start bridging with Lovenox then.

I hope this feedback about my own experience is useful.

 

[Sherryl]

Thank each of you for your valuable information & personal experiences. I feel much better knowing that it takes longer than a week to get back into range after Lovenox shots. Thank you for taking the time to give your input.

 

[Protimenow]

A few things:

As newmitral said, your meter should be fine. I've been using an InRatio (the original) that I bought from a vendor on eBay who bought it from a hospital or clinic that upgraded. I don't know how many thousands of tests were run on the meter, or how long it sat unused. The quality controls on the strips helps increase confidence in the test (I avoided the word ASSURE in describing this), but for a meter to be used in a clinical testing, there should be some pretty good accuracy and reliability engineered into the unit.

As long as your strips are current, your tests should be pretty accurate.

In regards to your blood flowing more easily than usual -- I'd like to clear up that this really has little to do with your INR. We have the first person who mistakenly called anticoagulation 'blood thinning.' The two aren't related. You can have 'thick' blood and a low INR and 'thin' blood with a high INR. (My recent warfarin refill came with a pamphlet that perpetuated some of the errors in anticoagulation information, describing warfarin as a 'blood thinner' and warning against eating greens -- people usually just throw these things away, but if they actually DO read them, they're seeing wrong advice).

If your insurance doesn't cover your InRatio strips, you may consider buying them online. I can't ADVISE you to do this because of forum rules, but you'll probably save money versus what Alere is charging.

Finally -- although a doctor told you that your range should be 2.5-3.5, I wouldn't stress too much about 2.1. With warfarin, 2.5-3.5 is actually a pretty narrow range. Plus, as others have said, while your body is again adjusting to warfarin, you'll have some ups and downs. Being temporarily slightly below that range shouldn't be that big a deal.