Hi everyone.

I would like to ask all of you on any of the Noac's (especially Apixaban) if it was explained to you by EP or GP how we know they are working for SURE. I know the stock answer is that they work in a different way to Warfarin and without any food or drug interactions will not vary as warfarin does. BUT knowing what my INR is does give me some confidence in warfarin, it just seems we have to just assume the Noac's are working as there is no test to confirm. Just about every other drug we take a blood test tells us if it is working and whether any adjustments need to be made as we are all different and react differently.

I am probably having to change from warfarin due to side effects, but need convincing the noac's do indeed work and also how a lower dose can work as well as the higher one. A difficult question I know but any thoughts you can give me would be really helpful. Many thanks Joyce.

22 Replies

  • Hi Joyce. Do you need proof that there is oxygen in air before you breath? There are I believe tests which can tell how much of the drug is present in you body but they do not do anything do confirm efficacy. The drug works in a completely different way to warfarin as you already know. Warfarin is a vitamin K antagonist and it reduces thrombins which are part of the clotting process produced by the liver. NOAC's work on Factor Xa (pronounced TenA ) which is a different part of the clotting chain.


  • Hi thats the way I look at - It never crossed my mind to think that it would not work . I went for my annual blood test at docs and nurse commented blood seemed a bit thin so must be.

    Had to go again as there were concerns about glucose levels, - flipping heck , not that as well.

    Got a flu jab as well .

  • Warfarin is fickle stuff and its effect isn't static because it gets upset by what we eat or by our individual metabolism. Thus an INR test is required to indicate how well (or how inefficiently) it is working. On the other hand it can be assumed that the NOACs do work because there's no reason why they should not be working.

    I think a lower dose may be for people with low body weight. One of the NOACs has a smaller dose for people under 60kg.

  • Sorry to intervene on someone else's post but I wonder if you would tell me which is the NOAC for people under 60kg? I have just been told I cannot use Pradaxa, as I weigh less than 50kg and so I am going to have to start on Warfarin. Thanks for your help.

  • Here's a link to a pdf file produced by Cumbria NHS comparing the 3 older NOAC's - you'll see that Apixaban has a small dose which is suitable for certain people:

  • Thank you for replying. I will check this out with my consultant. I do not seem to fit the exact criteria, unfortunately and I am very thin, in spite of being perfectly well nourished. Very annoying!

  • Yes, it looks like it's Apixaban. I have added the Cumbria NHS site to my favorites - full of useful info and some stuff I can't understand.

  • Rivaroxaban has a smaller dose, 15 instead of 20mg. I weighed 52kg when I started taking 20mg, so probably worth asking about that?

  • Thanks Buffafly. That is interesting. I wonder why the consultant has not suggested it? I will now ask! How are you getting on with it, as you are similarly tiny? I am less than 50kg and lose very easily unless I keep eating many meals a day. Have you had any side effects?

  • I was the same until I was put on Diltiazem! Then I ballooned, I suspect because it incidentally cured my IBS so I pigged out but it seems to have settled at 56kg now.

    I have had no side effects that I can definitely blame on Rivaroxaban. I have had some joint pain but as I already had osteoarthritis I can't be sure and Warfarin was a nightmare for me. I had never heard of the NOACs and my doctor told me to take aspirin which had very bad side effects so I stopped. As a result I was totally unprotected when I had several days of AF, racing heart etc at the age of 69. Needless to say I had not found this helpful group then!

    I hope you are able to change, good luck!

  • Thank you for your reply. I am not on anything at the moment as my various doctors/consultants have been trying to decide what to do with me and have finally decided on Warfarin. I am very up and down, because of having no thyroid and I take medication daily for that so the thought of another thing to add to the mix is not enthralling me. I doubt if I will ever get stable on Warfarin if you also found it difficult.

  • I guess the thyroid problem makes treatment more difficult. You can only try, some people have no trouble at all. I suspect my digestive dramas affected absorption. I know what you mean about the pills, I have five every evening.

    I hope you get sorted with something suitable.

  • Thank you. I hope you keep well yourself.

  • With all the checks and balances in the US and the UK where authorisation of drugs is concerned, I am as content as I am ever going to be that Apixaban does for me what it is supposed to and I take it on trust. The lower dose of Apixaban is usually given to people with renal impairment, low body weight or other reasons deemed vital by the physician.

    My cardiologist didn't say how he knew it worked, just that it was his preferred AC and it had the lowest 'bleed factor'. I've been taking it for 2 years and have no problems with it at all.

  • Well Jjoyce,

    You have asked a good question! I am on 150MG of Dabigatran twice a day. I am told it has a half life of 12 Hours. Had it withdrawn 24 hours prior to catheter ablation for AF and still it poured all over the couch when they took out the catheters after the op. They stuck on this pressure weapon which did the trick. What I can tell you is I feel a lot colder so don't sit around for too long and it takes me longer to warm up. But I suppose you get that as you get older (as old as my little finger and a little older that my teeth) 70. When I cut myself I take a long time to heal up and when I bleed, I keep bleeding. My blood is definitely thinner and a lighter shade of pale. I handle chainsaws and hedgetrimmer's so am very careful what I do with them. I just guess they WORK! NOAC's seem to me a better bet and without all that testing of the INR for warfarin. Get well. Dave.

  • There are many things in life Joyce that we have to take on trust and this is one of them. After all you accept that an INR reading of between 2.5 and 3.5 will keep you best protected from stroke. How do you know that?? Because that's what you have been told accept it.

    The big advantage with the NOACs is that unlike taking warfarin you are 'always' in the groove; protected, no matter what you eat or drink.

    Neil Armstrong really did go to the Moon you know.....

  • Actually you know you're protected with warfarin between INR's of 2 and 3. See this graph:

    which shows the stroke risk (clot or bleed) against INR. You can see there's a sweet spot between about 1.9 and 3.5.

    The problem with the NOACs is that you don't actually know what they interact with as there's no standard test to check their effectiveness. You have to rely on information from the manufacturers, and if you read up about some of the cover-ups and misrepresentation of data which happened during the trials, you might not find that so reassuring.

  • Yes Mark, I agree you do know you are protected with warfarin between INRs of 2 and 3 (or 1.9 and 3.5). The problem is you don't always know what your INR is.

  • Yes that's true. That's why I advocate INR monitors. I think everyone on warfarin should have one. I get a little frustrated when I see posts about people switching to avoid the blood draws and the time that wastes. I can do an INR test in less time than it takes to make a cup of tea.

    The cost of a year's supply of warfarin, a monitor and a pack of test strips is less than a year's supply of NOACs, so why doesn't the NHS promote them more? Are they just taking the easy way out?

    Rant over, for now!

  • Hi I've never been on Warfarin,so only had experience of Apixaban,I take 5mgs morning and evening,it is out of the body in 12hrs,I have no problem with this and very grateful that I don't have to alter/watch my diet!

    You have to note how many years of research goes into producing new drugs,which have to be fully tested before they are passed fit for use by NICE!

  • I'm with you Anne. I'm neither qualified nor interested in researching Big Pharma cover-ups Mark. That's why we have effective regulators. I'll leave it to them to uncover any irregularities that may occur from time to time. I'd be more concerned about the unregulated pseudo-medicines industry - pills and potions which are sold at an alarming mark-up in so called health stores under the supposedly reassuring guise of 'natural' remedies.

    I'm content in the knowledge that statistically, on apixaban, I have less chance of having a stroke than.......well, almost anyone. That's good enough for me.

  • I am new to having AF. Less than a week. What is are NOAC's please?

You may also like...