Recently, I had to take Marevan for a couple of weeks because Coumadin was unavailable in Petropolis and Rio de Janeiro's drugstores. I thought maybe if I took Marevan in the same dosage of Coumadin, I would minimize the risks of new clotting. I could never be more wrong. My INR that was 3.84 (target range for me, according to the doctors) has dropped to 1.12 in two weeks.
When I told my doctors, they said to me that in Marevan the dosage is not as it seems... The pill is not really of 5mg but 2mg or 2.5... I am quite cross about it. I feel like I have been fooled by the pharmaceuthic industry, for we buy their product because we must take the drug.
Have you got any thoughts on that?
Written by
BrazilianBade
To view profiles and participate in discussions please or .
I use Marevan and it says in the information that comes with it that different brands of warfarin are not interchangeable. Not to switch from one to another. You need to stick with one brand and get the dosage correct for that brand.
I used marevan 5mg for about two years, switching from a UK manufactured generically called "Warfarin" 5mg tablet. I didn't experience any issues with the transition, which makes me think your incidence is a bit odd. Is Coumadin just warfarin or is it a product of Warfarin? If the latter, then the half life of the drug might be different. I hope you get to the bottom of this!
Hi, Thomas, this is actually the second time it happens to me... Coumadin makes wonders to my blood and when it vanishes from the market I need to take warfarin and the inr drops drastically. I cannot remember when, but once I was told that Coumadin has coumarine in its composition besides the warfarin...
As I have previously said, I am taking coumadin again and my inr is perfectly fine, inside the target
My doctor told me I am not the first patient who describes a situation like this... Maybe, it is worth gather as much information from patients as possible and sue the lab because of the risk we are subjected to...
Should I believe what stranger who I am sitting by on a plane tells me? Once, years ago, such a stranger who was married to a drug rep told me that the subtle differences amongi various manufacture formulations were often only known to the manufacturers themselves.
Okay just repeating as I think you may have missed it. In the booklet that came with my Marevan and you can ask the pharmacist for it says:
"Are Coumadin and Marevan the same? The simple answer is NO. Coumadin and Marevan are intended to work exactly the same way; however, their formulations are slightly different. Unless directed otherwise by your doctor, YOU SHOULD ALWAYS KEEP TAKING THE BRAND YOU WERE FIRST PRESCRIBED."
My apologies for caps but it was in bold font and I can't bold the font here.
Maybe, in the UK, they specify that they are different, however, in Brazil (perhaps lab interest or translation mistake), both Coumadin and Marevan are told to be sodic warfarin.
Yes they are both warfarin but the way they make them (the recipe) is slightly different so they behave differently if that makes sense?
So basically if you do change brands only do so under medical supervision and you will need to adjust the dose all over again like you did in the beginning and get your INR checked more often to make sure its ok.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
Has anyone experienced Renal problems with APS
Has anyone else had problems with an employer? Is APS covered by the Equalities Act?
Has anyone with memory issues had a neuropsychological evaluation done? 
Has anyone had similar symptoms?
