Missed dose or going mad? : If you forget a... - AF Association

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Missed dose or going mad?


If you forget a dose of warfarin, will it have a massive effect on your INR result ? I'm booked in for ablation next Thursday and I'm driving myself bonkers trying to remember if I took it tonight or not. I think I did as I remember thinking I would take it before dinner, but don't remember putting them in my mouth! Does anyone else do this to themselves? I could weep as my INR has been within range and can't believe I might have messed it up one week before my proceedure. Will it have time to "recover" so to speak? My INR test is on Tuesday and I get the result the next day which would be too late to alter/increase it. Can anyone reassure me I'm really panicking

46 Replies

The answer is that yes this will make a difference to your INR reading. We have probably all been in your position. I certainly have. Don't risk taking a double dose though. Could you perhaps phone your clinic and explain the position. What was your last INR result? If you are well within range you might be OK. Perhaps you can adjust with food. Rosy G is very clued uupp on this a and will probably advise you.. Sandra

Mommamia in reply to Hidden

It's been 2.5 for two weeks and 2.2 week before that. I keep trying to remember and the more I try the more anxious I get. I've got to be above 2 for it to go ahead. I wonder if dr will let me have earlier test on mon which gives me time to tweak it if necessary....... Thanks for replying I'm so worried

Hidden in reply to Mommamia

I would keep off green veg and see if they will test you monda6, for your own sanity! Try not to worry , what will be will be and you may be perfectly OK.

Mommamia in reply to Hidden

Thank you. Fingers crossed x

lingooz in reply to Mommamia

I had this experience was told .not to take another inr was fine , I know put my meds boxes in order of times I take them on worktop and soon as I take pill I put that box at back and ends up warfarin is at front being my last pill at 6pm also my mobile is set to go off each day at six !! Hope this helps and good luck with ablation x

Mommamia in reply to lingooz

Yours was ok? That's good to hear x

I know how you feel! Have just sat here thinking did I take my warfarin- answer is yes I did, remembered because of the coloured tablets I took! My inr range has been fine until I started taking amiodarone and then it shot up and has been up / down etc. hope everything it goes ok x

Mommamia in reply to Jollies

Thank you. Pray for me

Jollies in reply to Mommamia

Of course. Worry ye not! X by the way I feel the same way as you about the pillboxes, but am now thinking drat I'd better get one x

Hilarie in reply to Jollies

I have had exactly the same experience Jollies. My INR was stable and then I took amiodarone and it shot up, lowered and then shot up to 6. I then had to take a dose of Vitamin K dissolved in water and had a blood test two days later when my INR was 1.2. I have been on amiodarone for the last month and it has made me feel awful so I have now come off it. Apparently it stays in the system for 3 weeks. It certainly causes havoc with the INR!

Jollies in reply to Hilarie

I have had my cardioversion today, this time it worked. The amiodarone doesn't seem to suit me either. Have a review with my EP soon and will ask when I can come off it x


Whatever happens if you buy a seven day pillbox from Boots or similar you wont make that mistake again !


Pdotg in reply to BobD

My Sunday routine: cutting up the blister packs and counting out all those pills, still blistered, into one of these 7 day boxes. I keep it next to my bed to remind me am and pm. Seems to work, even with my butterfly brain.

Hidden in reply to Pdotg

Yeah ... I do that too - but occasionally still forget. So, now I also have an app on my android smartphone that goes into non stop alarm mode (sends the cat ballistic) until you switch it off - which I do when I take the pills. Works a treat ! App is called.... Dosecast. You can programme it for every pill you take, time of day to be taken, alarm to tell you when you are due to take pills, even a postpone bit if you are going out partying and want to delay taking pills. Excellent.


Beat me to it, get a pill box or make one up from something, just 7 compartments is all that's needed. Load it up and take the pills from there, then you can't forget, unless of course you forget to look at the pill box. I have reminders on my phone and computer and ipad !!!! to remind me to look at the pill box. And I still forget sometimes.

Hope it doesn't upset your ablation. My INR dropped out of range a few days before my last ablation and they went ahead anyhow in my case, so fingers crossed.


Mommamia in reply to Hidden

Thank you! Gonna dig out the pill box and stop being stubborn (pill box made me feel old and decrepit) fingers crossed and hope my GP is sympathetic tomorrow when I tell him what an idiot I am

Mommamia in reply to Hidden

What was your INR when they went ahead ?

Hidden in reply to Mommamia

I can't remember Mommamia, but it was over 2. They gave me a higher target before the op for some reason and it went up but then dropped again.

I have to turn round 100 yards from home and go back to check that I locked the door. Always have, but that doubt creeps in. When it's such a routine thing you do it so automatically that it doesn't register. So you probably did take your warfarin. I would think with a week to go it would even out if you didn't. But easy on the greens, as Yatsura says. You can be on the high side without it being a problem.

7 day pill boxes keep you on track and you know where you are.

Mommamia in reply to Rellim296

Ha! You sound just like me, I drive back home to check I've turned my hair straighteners off to find them unplugged and put away in a drawer stone cold and I'll have no recollection of putting them there!!! I think I took them tonight I've just gotten myself in a tizz as it's so close to my ablation so it matters a lot this week. Thank you for your reply, knowing I'm not the only mad one really helps x

Rellim296 in reply to Mommamia

The iron is a good one too. I once (about 32 years ago actually) had to ring my neighbours to ask them to go and check it before the house burnt down. It was off of course.

Hope your ablation will go well and will move you forwards the way mine has. Take something funny or absorbing to read while you wait.

All the best, Lisa

I think I forgot my tablet (not warfarin) one day last week and could not remember for the life of me. The more I thought about it the less clear I was. I rang my pharmacist and asked if I was safe without it. He assured my I would have enough of the drug retained in my body to suffice until my next tablet was due .

the following morning.

You probably did take it out of habit and on automatic pilot. You will be ok try not to worry too much. Best wishes for your ablation. Take care.


Mommamia in reply to meadfoot

I think I took it as it was on my mind, it's amazing that I just can't remember, as you say...... Auto pilot. I'm just anxious that I'll drop out of range and my ablation will be cancelled. I'm geared up for it now. Going to speak to my dr tomorrow to see what he advises. Thanks for your reply.

I have done this twice but then realized I must have taken it without thinking as my I.N.R. was ok 2 days later. I have just bought a pill box so it can't happen again.x

Mommamia in reply to dedeottie

My daughter bought me a pill box and like a stubborn fool I haven't used it as I still can't believe there is something wrong with my heart! Regretting that now big style

Feel like such a fool. Can't stop worrying about it now

Ave an app on my phone called Med Helper. Brilliant .Lists all your meds .I have it as an alarm as well so at 6 pm the alarm goes off ,the app flashes on the phone and I have to tick off each med I've taken.I also have given in and use a pill box (hated that- used to think only for old people - it's not it's a fail / safe , if you think logically ) .I used to forget pills all the time ,since the above never forgotten a pill in nearly 2 years.

Good Luck with the INR .I hope you are stable.


Best of luck with the ablation, I am sure all will be well, makes me smile, we are all truly in the same boat with our memories almost regardless of age, I think it is more to do with the fact that it is such a familiar automatic daily process, rather like driving down a familiar piece of road and not quite remembering whether we have done it or not!


Maybe you should get a pill box I use it for mornings and evenings if I take my evening meds I then open the next morning box ready I can see which meds I have taken by the empty box, 1 have never had any doubt..... have I taken my meds or not must be awful for you.

So a pill box for you I think, don't worry it will turn out ok in the end...My pill box was from Boots.


I put my daily dose in a tumbler at breakfast time and have an alarm on my phone to remind me to take it. What is it about pill boxes that we don't want to use them - along with round the neck glasses cords and shopping trolleys!!

I am sure you will be fine Mommamia. Best of luck for the ablation.

Best of luck for the ablation - I have the same problem, I am really pants at remembering and it's true, as everyone says, you do it on autopilot so it's hard to remember. I had to give in and have a pill box - and two alarms, one on my phone and one a teeny pillbox alarm, so I am sure to remember! And even so occasionally I've managed to forget. I'm sure you didn't, it's the worry of the op that's making you doubt yourself. Take care and use that pill box :)


It is best to have a pill box with compartments for each day. I make my pills up for the week. I used to get myself into a state at times forgetting. I have missed a dose but still been in range following week. sending good wishes for a successful ablation.

I too have been in your position many times, but your being in range is really important now your ablation date is near. I would tend to be on the safe side and talk to your GP today and ask if you can perhaps take an extra milligram or 2. What dose of warfarin are you on now?

I'm on 3mg daily and I'm pretty stable at 2.5. I can go up to 3.4 but not below 2 so I can afford to increase a bit if I did take it, but not dip if I did forget. G.P has suggested extra 1mg tonight only then back to 3mg sat, sun and mon. She thinks I should be ok.


This is so easily done; I'm sure nearly all of us has on occasion taken our medication on 'autopilot' and then found it impossible to recall doing so a few hours later! A pill box certainly does help. My own remedy is to say out loud to myself (I live alone, so no one else can hear me!) 'I have taken my warfarin' or 'I have now shut and locked the front door' when leaving home or 'I've unplugged the iron' just before going out. It helps me tremendously - hopefully, it may help you too!!

All the very, very best for the ablation procedure, and of course you'll be in my prayers for a successful outcome.

Peter A

I don't bother with pill boxes, I just mark the 14 tablet pink strips (5mg) over the tablets with the days when I have to take them with a marker pen - so SU, MO, TU, etc. It works well and is very easy and quick. I also can't remember if I took tablets sometimes and a quick check shows whether I have. I take a blue (3mg) at the same time but I don't bother to mark that up as I only ever take it with a pink.

I think missing a dose would have a temporary effect - dropping your INR to around 2.2 until gradually recovering over about 4 days. So with a week to go you should be fine. You could always arrange a test for a day before so you could carry out an adjustment if it's a tad too low - but it would have to be a significant amount to impact you INR - for me that would be around a one-off 3mg to boost your INR by around 0.2 by the next day.


Isn't it a positive nightmare when you find yourself in this situation.

I know as I do it occasionally and feel that I'm so stressed about it , something terrible will happen.

Ring your GP or the hospital. They will put your mind at rest.

Good luck.

Hi everyone. Thank you for all your wonderful comments. I'm a bit calmer today, but only just!! My g.p was lovely but agreed it's not an exact science so difficult to advise with a clear outcome. I'm to take an extra 1mg tonight and then revert to my normal 3mg sat and sun and blood test changed to Monday to see if there is time to tweak it before Thursday. Not sure though if I am too low on Monday if the will refuse to do proceedure on thurs.... Even if I get it back in range by wed as you have to declare all of your results I think? Will they be happy with a result the day before in range ????


Dont Worry, I have done that as long as you take it the next Day it should be ok, or you are allowed a few hours i think on same day, but i have missed mine and my INR has still been fine, i think if you miss a few days then yes it might afect it, but if you are not sure just give them a ring.


Mommamia in reply to suzytoshoes

Thank you, I am calming down a bit now .... I wouldn't worry so much but obviously the next INR is crucial to my ablation going ahead next thurs. I'm taking an extra 1mg tonight which might soften the blow so to speak.

I use a pill box and am naturally a very organised person but the other morning I opened it for the morning tabs and hey ho sitting there was the previous nights warfarin and beta blocker. How on earth did that happen? So, I added an extra mg on various days during the week until I had covered the discrepancy. Lesson - yes use a pill box but also some other audio, visual reminder if you have to take tabs at different times.


Like Fi

I use an app, in my case called Medisafe, it "shakes a pill bottle" at me to remind me to take my meds, and also my problem is that I am out so many evenings so I forget to take them when I get home, and this reminds me, and now I have a "one day" antique pill box with my evening meds in which I simply fill when I am going to be out in the evening.

It also lists all the times and dates when I took my pills ad nauseam for anyone really interested (I'm not)

Be well


What do people think to the extra 1mg tonight? will it make much difference either way? Thanks everyone for your responses, your all keeping me sane here. Xxxx

rosyG in reply to Mommamia

I'm no expert, but my GP is happy if I vary by a mg, I think Yatsura's idea about avoiding green veg would also do the trick, assuming you normally have some green stuff??

I know I can find my INR moving a bit too high if haven't had the usual green vegetables.

Good luck with the ablation, Oh and you probably did take it- it's happened to me a couple of times, just as you describe, and my INR hasn't gone down when I've tested in a coupe of days

ILowe in reply to Mommamia

For people not in a hurry, the standard advice if you miss a day is, if you notice before midnight, then take it normally. If not, then ignore the miss, carry on as normal. Eventually the body will catch up. That is the theory, and I think it is a little simplistic. It works best for people on long term Warfarin, and on the old system where a wide range of INR was tolerated. It is also the default behaviour if you are not sure, and the advice is not that bad.

The next level of reasoning is to add something to the next 1-3 days, in order to partially catch up. This is important, you only need to *partially* catch up on the dose because of the clearance mechanism. It is very important to NEVER double the dose, and never supplement drastically, because you do not want to create a dangerous swing. So, if you are on 3mg and miss a day you might do +1 then normal as several have suggested. If you were on 6mg I would step it as 8 then 7 then normal 6.

I said above, that the standard advice is a bit simplistic. The only advice/training I ever received before starting to self-dose was that the best way to think of it was like charging a paintbrush. The paintbrush needs a "charge" and regular consistent topups. If the topup is too great then the charge increases. If the topup is too little then the charge is decreased. Your target INR is that charge.

Another useful picture is that of a reservoir. When you achieve steady state, then the height of the reservoir is stable (the target INR) and the inflowing water (your warfarin) matches your outflow (warfarin clearance). Missing a day is like stopping the inflow for a day, but clearance still continues. When you restart at a normal rate then you restart at a lower reservoir height. To restore the height after a missed day does NOT mean doubling the input for a day, because that creates swings, and swings are the real problem in INR control. Hence another principle: All changes must be made gently.

Sorry to hear you may have messed up...we have all been there..it only takes a distraction!!

This might sound a bit OTT but you need a sort of little ritual.....I set my alarm on my phone for 6pm, but could still be elsewhere in the house or distracted, ignore the alarm and forget......so I have a piece of card with Warfarin written on it, that I keep with my meds in the kitchen. Some time between and 5-6 when I am usually cooking dinner.......I pop out my Warfarin dose out of its pack and lay it on the card.......when I take the Warfarin, I turn the card over and then put it back with my meds till next day. It works for me!

Hope you are OK and not delayed by your mistake!

Good Luck

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