Interactions

[LondonAndy]

You may find this thread from a couple of weeks ago useful. In my case antibiotics increase my INR.

 

[tom in MO]

Antibiotics Interactions ?, Dealing with some issues that will require taking antibiotics soon,
any body has experience in the interaction between Warfarin and Antiotics ?, What to Expect ?
WIll INR go up, or down ?, or no change ?, Thank you for your comments,

Ask the prescribing physician if it will interact with warfarin. Verify this is correct by calling your cardiologist's nurse and tell them what you are taking. Sometimes it's no big deal. Sometimes they want an INR test at a certain time.

 

[mecretired]

Ask the prescribing physician if it will interact with warfarin. Verify this is correct by calling your cardiologist's nurse and tell them what you are taking. Sometimes it's no big deal. Sometimes they want an INR test at a certain time.

I have been on a lot of different antibiotics over the ten years that I’ve been on warfarin. Generally they have little effect on my inr. I really think that everyone’s body reacts differently. Get your doctor’s advice. Check online sites for interactions. Bottom line—you will need to see what that particular antibiotic does to your inr.

 

[Protimenow]

Antibiotics WILL usually change your INR. This is because it kills the bacteria in your stomach and intestines that helps break down food (or whatever goes down there). I don't recall, exactly, if it raises or lowers your INR, but if you're on an antibiotic for a few days, and you have a meter, it's a good idea to test your INR after a day or two - and maybe again a day or two later.

A few days with an INR below range will probably not be a big deal -- a few days with it above range probably isn't (as long as it's below about 5 or so).

Maybe someone else here will know which way your INR goes when you take an antibiotic.

 

[vitdoc]

In theory some gut bacteria produce vit K. So there may be a reduction in K and a prolonged INR. Not sure how significant this is.

 

[ScribeWithALancet]

What you are advised by doctor professionals is cranberry juice more than anything. There is an enzime that can mess with your INR. Just ask your cardio or other medical professional on what they know what you should be consistent on your daily intake. I never go by so called medical articles unless they are in New England Journal of Medicine. Reliable sources. Hugs for today.

My previous endocrinologist was a research doctor. He called the New England Journal of Medicine the most dangerous publication in the United States. This was because of it's high reputation. It's articles will make the front pages of newspapers across the US and the evening news. Unfortunately, it's retractions make the back pages of newspapers across the US and never make the TV news broadcasts. For you, it is probably safe, as you will read the retractions as well as the articles.

Walk in His Peace,
Scribe With A Lancet.

 

[LondonAndy]

Today I finished a 5 day course of a mix of 2 antibiotics: 500mg of Phenoxymethylpenicillin and 500mg of Flucloxacillin four times daily for an infection of a leg injury. The effect on my INR was to reduce it by about 0.5 I think. I didn't make any particular changes to my diet, though my diet is not particularly consistent anyway; hence the approximate INR reduction stated.

 

[user 15848]

Antibiotics is for sure something to keep in mind; heard some do have some interactions others dont, but when ever something changes in our lives i think is a good practice to increase the frecuency of testing, just a thought..

 

[pellicle]

I really think that everyone’s body reacts differently.

pretty much this.

I've been on amoxicillin for the last 7 (and a bit) years and my INR is pretty much still taking the dose that it was on before I started antibiotics ...

 

[pellicle]

The effect on my INR was to reduce it by about 0.5 I think.

pretty much within what I'd call normal variance, how does that sit with your observations of your INR variability outside of this context of antibiotics?

 

[LondonAndy]

pretty much within what I'd call normal variance, how does that sit with your observations of your INR variability outside of this context of antibiotics?

That is a significantly larger larger variation than I would normally see between one week's test and the next: +/- 0.2 is more the norm.

 

[Astro]

Being alive for a week seems to frequently cause an interaction with my warfarin. Haven’t worked out whether it causes it to go up or down - seems to go either way.

My point - it would actually be quite difficult to prove interactions above the normal noise of warfarin. Randomization, statistics and many people would be required.

 

[pellicle]

My point - it would actually be quite difficult to prove interactions above the normal noise of warfarin. Randomization, statistics and many people would be required.

There are however soon pretty well established ones. Anything which interferes with Cytochrome P450 for instance

 

[pellicle]

That is a significantly larger larger variation than I would normally see between one week's test and the next: +/- 0.2 is more the norm.

That could be, but it's still not a big variation, a whole unit would be significant