Question for those that have been on warfarin pre and post surgery….

[sarahsunshine]

We’ve noticed that Skyler’s warfarin dose does not seem to work for him post surgery. Both his INR thrombosis clinic and us thought that going back to his previous schedule would work nicely (alternating 8mg and 8.5 mg). This used to keep his INR around 2.7-3.2 range, with occasional fluctuation around that depending an diet and exercise.

Well, he recently got off his intravenous antibiotics, we gave him a couple high doses, and then went back to his 8/8.5mg, assuming all would be fine. All was well for the first week, but we tested after a week just to be sure, and lo and behold his INR is 1.7! WOAH! Completely unexpected!

No, we’re not panicking. I’m just wondering if anyone else has experienced this before.

I assume that the change is due to the increased blood flow (3x the blood flow going through his heart in a single beat), his weight gain (he’s 7lbs heavier than pre-surgery 2 months ago!), and increased exercise. All these things are wonderful! I was just very surprised at the change in warfarin! I expected a small change (maybe 2.5 average) due to increased activity and blood flow, but why wouldn’t the thrombosis clinic even mention that?

We’re aiming at a lower dose (2-2.5INR) with aspirin, so, in the meantime, we’ve upped his warfarin to 8.5 daily and will test again on Saturday. I just hope his mom complies…

 

[dick0236]

Well, he recently got off his intravenous antibiotics, we gave him a couple high doses, and then went back to his 8/8.5mg, assuming all would be fine. All was well for the first week, but we tested after a week just to be sure, and lo and behold his INR is 1.7! WOAH! Completely unexpected!
…

Could have been the "intravesnous antibiotics", since antibiotics can play havoc with INR. Could also be the weight gain and exercise.....or it could be a test variance. 1.7 is not too bad and testing once per week until he finds his "new normal" should do the trick.....but, since this is soon after surgery(?), work with his doctors .

 

[sarahsunshine]

There shouldn't be any antibiotics in his system anymore, he got off them on Jan 22. He's now almost 3 weeks off of the antibiotics. The 1.7 test was 2 weeks after he has been off IV antibiotics.

I also doubt it's the test variance (I know there's some variation, but a full unit?), since all the tests that he's done have been on our same home CoaguChek XS machine for the past 5 years, and at our annual calibration with an intravenous test, it consistently comes out 0.1 less.

I realize that the 1.7 isn’t too far off 2.0-2.5m but his same dose kept him around 3.0 previously! We'll see how he comes out this weekend.

There's also the possibility that it's also decreased because of stored K2 in his system. Vitamin K can stay stored for up to 1 month, and while he was off warfarin we dosed him up on K2 for a while.

 

[sarahsunshine]

Well, his mom didn’t test him for another week, and when he was tested, after having his warfarin upped to 8.5 daily, his INR was down to 1.6. So we talked about it with the clinic (we are self-regulating) we decided to try him on 10mg for 4 days, test, and re-evaluate. Called the clinic and they said that it sounded good. Tested on Thursday and his INR was 2.6. DH wants to try to keep it lower, so is trying 9.5 this week. Will test again on Wednesday and see how it goes. I suspect it may still be rising. Just a hunch, though.