Given two options to slow rising INR - which one to do?

[DanielB]

I started a two week course of Bacrim (an antibiotic) for a urintary tract infection last Friday, knowing it can cause my INR to rise. My Coumadin nurse had me test Monday and my level had risen from 2.3 (my norm of late) to 2.6. I did a retest today and it had gone up to 3.4 - higher than I have ever had it. The nurse gave me an option of reducing my dose by half starting tonight, then restesting Tuesday or leave it alone and retest Saturday. I chose the halving of my dose with the retest Tuesday.

Since I am pretty new at the coumadin dosing thing, I would appreciate some input from some of you that have a lot more experience on this sort of thing as to which option may be better a better way to go. I can still change my mind today if if I feel the need. In any case, I'd like to learn more about this situation for future reference.

Thanks!

Dan

 

[dfelder]

3.4 is not critical and I would have made no changes. Reducing by half seems a little extreme to me. What is your range and what dose are you taking?

 

[DanielB]

Reading the literature on Bactrim since I posted , I see that Bactrim can add as much as 1.76 to one's INR, so I suspect that's why they were thiunking the decreased amount.

My range is 2.0-3.0, dosing is 5MG a day except Tuesday & Thursday when it is 7.5mg.

 

[Bill B]

I wish they could have found another antibiotic other than Bactrim for your infection. Bactrim has one of the most significant interactions with warfarin. You are almost a week on Bactrim, so this may be as high as you go. 3.4 is not terribly high (high therapeutic range from many valves), so I would have no real problem testing Saturday, per chance it might just stay at 3.4 or just slightly higher. BUT sometimes the INR doubles with Bactrim, so your choice to halve your warfarin dose and retest Tuesday would be more consistent with that possibility. I'd do the former.

 

[DanielB]

Thanks Bill - I was just told that Bactrim can double the INR. I was put on Bactrim after Cipro didn't do the job, which it should have. The good news is the Bactrim is working for it's intended purpose.

Part of the issue of course is Monday is a holiday, so I suspect they would be approuching this a but differently if they were in the office Monday.

I see my cardiologist next week (by coincidence) about getting into home monitoring -- boy that would be nice to have now!

Dan

 

[Jailene777]

You chose best. Half your dose. I did that one time. I even went 2 days without taking of how high it was. I was sick because of the INR level. Its essentially rat poison, so our body can tell us when we are at a level of toxicity. I had a CT scan done on my head to make sure I wasn't hemorrhaging. I had a terrible migraine that had me in tears. I was taken to the hospital by ambulance, thinking I was hemorrhaging. Bactrim is another story, that medicine depressed my system to the point that I was lethargic. Be careful with your meds.

 

[catwoman]

You chose best. Half your dose. I did that one time. I even went 2 days without taking of how high it was. I was sick because of the INR level. Its essentially rat poison, so our body can tell us when we are at a level of toxicity. I had a CT scan done on my head to make sure I wasn't hemorrhaging. I had a terrible migraine that had me in tears. I was taken to the hospital by ambulance, thinking I was hemorrhaging. Bactrim is another story, that medicine depressed my system to the point that I was lethargic. Be careful with your meds.

And what was your INR when this happened?

 

[Protimenow]

IF you got sick because of a high INR level, you'd have had a lot of other symptoms in addition to a headache. If the INR was high enough to give you a headache, and possibly even a brain bleed, you probably would have had pretty persistent hematuria (blood in the urine), you probably would have had blood in your stool, and your gums may have also bled a lot. You may have had bruising on your skin. This would certainly have been life-threatening and would have exhibited as much more than just a migraine headache. Sometimes a bad headache is just that -- a really bad headache. (The non-coagulation symptoms that I mentioned above can also be due to some types of liver failure)


(FWIW -- although warfarin has been used to kill rats, many of them have developed an insensitivity to warfarin, so other chemicals are now in use.)