My step son has been on warfarin since he was 5yo for his mechanical mitral valve. I have done a lot of research on warfarin, but it’s been a while. I’ll tell you want my research and experience has found.
First, I’ll deal with experience, and some may not apply to you since my step son is a growing boy (now 12).
Home testing:
Since I’ve been on the seen (6 years) we have been doing home tests. This is a total time saver. If you have the option, DO IT! If you are having trouble with your levels, it’s easy to call the clinic and ask for help and advice. I’ve found from long term use that a lot of the time we know better than the clinic what will affect the dose and how to make a change.
Insurance:
Depending on your insurance, it will cover everything to nothing to sometimes covering it and sometimes not! Weird, I know. My husband’s insurance coverage used to cover the strips for 80%. Then they didn’t, then they did. They didn’t cover the home machine, but the clinic that my step son took part in did.
Then we discovered that my insurance covered both the machine and the strips. Now we have 2 machines, so that stepson’s mom can have one at her house (though she’s never used it in the past 3 years).
Stepson’s mother’s insurance doesn’t cover the machine or the strips. I guess they’d be in major debt if I didn’t have insurance through my work!
Dose management:
Some people have a hard time with this, others don’t. A bunch of the studies that I’ve read suggest it has to do with vitamin K. The way Coumadin/warfarin (same thing) works is by blocking vitamin K from working in the blood clotting process. The dose that is required is enough to counteract the vitamin K that’s in your body. Originally they tried to limit the amount of vitamin K that people ate and make sure that it was consistent – this would get you the lowest Warfarin dose possible. Unfortunately, only small amounts of vitamin K can drastically decrease your INR (International Normalization Ratio - a measure of blood thinness) levels, making you blood clot more easily. This is bad if you are trying to keep your blood thin (most people’s blood INR is 0.9-1, most people with mechanical heart valves need to maintain an INR between 2-3.5). More recent studies I have read suggest that you should increase your vitamin K because your body stores a certain amount for a certain amount of time, and the rest is peed out. Then you get a more stable dose of warfarin (though higher).
What happens if my INR gets too high?
One of the greatest things about home management is that if you are covered by insurance, and you “feel something is wrong” then you can test. No hastle, no rearranging schedules, no problem. On warfarin, you will notice that you bruise more easily. You may also get frequent nose bleeds. Nothing much to worry about. If you have more bruises than normal, or more nose bleeds, then maybe your blood is thinner than it should be. Check. We have a dose of liquid vitamin K in our fridge. If my stepson’s INR is too high, we are to call his clinic, and they will possibly give us a dose of vitamin K to give him. Supposedly it works in minutes. The problem is the doseage. You really don’t want your INR too low. Note, this is only if the number is WAY TOO HIGH (over 7). If it’s just high, (under 5), then we are just to lower his dose for a couple days and then go back to the usual dose, and test again in 3-5 days. If it’s over 5, we are to call the clinic and make our way gently to the emergency room (no bruising please)! It’s never happened for us.
Typical PITA things:
If you have to be on medication, you need to make sure you keep it on hand, don’t run out, keep up on the tests, and keep track of your diet. If you are someone who does this anyway, you should have no problem.
Testing frequency:
The way we do INR testing is basically once a week, always at the same time of day, preferably 12hrs off of the time you take your dose. (evening if you take your dose in the morning). This is because warfarin stays in your system for about 72 hours. If you test at the same time that you take it, you may or may not be including your current day’s dose in the test. Therefore, INR doses can be way different if you take it in the evening vs in the morning!
Health issues related:
There is some debate about which is cause, effect, or spurious (otherwise related) correlation. People on warfarin tend to have higher incidences of heart disease (really? Isn’t that usually why they take the warfarin?) However, there is also a correlation with calcification of the arteries that could be explained by the fact that since vitamin K is taken out of the clotting process, then what happens with the other factors that would normally be reacting with the vitamin K? Yes, they are the same things that make up the artery calcification. The good news is that theoretically, if you stop taking warfarin and have high levels of vitamin K, this is reversible. So if you get a tissue valve later, you could theoretically decrease the calcification of the arteries. Of course, if you increase vitamin K levels to decrease your calcification with the mechanical valve, then your INR level would crash, and your warfarin dose would increase to compensate for the lower INR value. All in all that would be a bunch of money paid for vitamin K and warfarin literally down the toilet…
Another consideration is low bone density. One of the side affects of warfarin is low bone density, and therefore an increase in chances of having broken bones and osteoperosis.
I think that’s covered what I’ve looked into. Of course, many people have no issues at all.
