High INR and Kelp

Sean · Mar 5, 2004

Hi all,

I have a question. Here's my situation first. About three weeks ago my INR tested at 3.9 (ProTime tester). I adjusted my dose so it would go down to my desired range which is 2.5-3.5. Tested again last week, it was 3.2. Fine. Last Sunday I started taking Kelp as an iodine supplement because I'm trying to stay on a low salt/sodium diet and I read that this could leave my body low on iodine. Today I tested to make sure that my newly adjusted dose doesn't send my INR any lower than 2.5. My INR was 4.2! I went online, searched for Kelp and Coumadine and came up with some mentions of possible interactions. Can someone tell me if this is a well known interaction? I'm pretty positive this is it, since my diet is pretty steady, as is my lifestyle overall, but a confirmation would be great. Also, does anyone know of a good iodine supplement that wouldn't interact with Coumadin? Thanks loads.

Peace.

Sean.

bvdr · Mar 5, 2004

Hi Sean,

I don't know about the Kelp/coumadin interaction but it may do that to you even if it doesn't to other people. I've noticed that fresh pineapple can raise my INR and it may not have that effect on other people.

I like my INR up around 3.9 but I have a history of an embolus to motivate me to keep it up there a little.

Do you eat much seafood? I believe that is a good source of iodine.

RCB · Mar 5, 2004

Iodine need small

Iodine need small

I was told one can of tuna fish a week will meet your iodine MDR.

Guest · Mar 5, 2004

This is very difficult to explain

Kelp is rich in iodine. Adding iodine decreases the function of the thyroid. Decreasing thyroid decreses the metabolism of vitamin K dependent clotting factors. Decreasing the metabolism of clotting factors means that you are more likely to clot.

BUT

The opposite seems to happen first. For some reason the INR seems to go up at first. I got lulled into a false sense of security on this paradoxical reaction once and the lady had a stroke because I wasn't monitoring her as often as I should have been. I thought the INR was stable and all of a sudden it dropped to almost 1 and she was admitted to the hospital. Fortunately she had no lasting effect.

Now I get very worried whenever somebody messes with Synthroid, Tapazole, Propylthiouracil, Kelp or other iodine containing things.

As a new warfarineer one of the things that you will have to learn is that stuff people say and write about many supplements and a lot of advertising no longer applies to you. They simply leave out the warnings in trying to sell products.

Sean · Mar 6, 2004

Thanks for your replies. Please tell me if I'm understanding this correctly. Kelp is NOT the problem here, it's the iodine (well, kelp may be responsible for the sudden jump in INR), and if I hadn't stopped taking the supplement in response to this jump I should have expected a decrease in my INR. But if I waited it out and adjusted my coumadin dose accordingly, I could take the supplement as long as I kept it steady. Consistency is the key here, right? Just like with salads and other foods, except those don't make your INR jump up and down at first? Or is there something in some supplements that makes your INR become consistently unstable?

Thanks again.

Guest · Mar 7, 2004

You have it correct, Sean.

Each ingredient in each supplement must be considered the same as if you were adding a new prescription drug. Some supplements can have quite serious consequences with warfarin.

There are no drugs that cannot be given with warfarin. When it says that they interact that does not mean that you cannot use them. It means that you probably will have to adjust the dose.

You have to also remember that stopping an interacting drug is just as serious as starting one, the warfarin dose may have to be adjusted weekly for a month or so.

The interaction with the iodine in the kelp is dose-related. If the kelp is not standardized in terms of iodine content, then you will be on a teeter-totter forever. The really sad thing about the dietary supplement law is that it does not require the pills to actually have in them what the label says that they do. So you are never quite sure, even if you are buying the same brand.