How is Flecainide when taken in the long term - AF Association

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How is Flecainide when taken in the long term


I have been a lone paroxysmal AF patient for around 40 years , starting very young around 21 years old, they were very few and far between until the last 10 years, then I was put on Sotolol for around 8 years being taken off because of very slow heart rate. I was then put on Flecainide and are finding the side effects very trying, such as tiredness and dizzy spells . I was wondering if anyone else has had the same problem and carried on taking them.

42 Replies

Hello Linbobs, interesting to read reading your concern. Following an ablation 3years ago the cardiologist decided to put me on flecanide. Wrong thing to do, with no time at all I began to feel as thought life was draining out of me altogether. Whilst trying to get myself together following the ablation I decide to make a stroll around the block. Possibly 100 yds within halfway round I just felt as thought I was going to collapse had to literally had to drag myself home. What an experience! Cardiologist was brilliant, he phoned me at home, saw me following after all his consultations and decided to put me on Amiodarone - made such a difference. We still discus that time even now! But then drugs have such a different reaction with everyone. Hope all goes well, let me know.


looby1660 in reply to migmog

Hi, I know this is an old post, don't come on here very often but just seen yours. You are quite right how we react to different meds. I am stable on Flecainide and have been for about 20 years although I do have occasional bouts of fatigue however Amiodarone!!! Side effect city with me and that drug!!! Damaged my natural melanin and a few other things I can't remember now except for one thing I'll never forget, about 2 years after swapping from Amiodarone to Flecainide I started to have thyroid problems. My GP told me that the Amiodarone was so potent and had lingered in my system giving my hypothyroidism 2 years after I stopped using it!!! I had some corrective therapy and all is well now.

I hope you continue to do well on the meds that suit you, but just keep an eye out for thyroid issues, I'm sure you've been briefed about the side effects anyway.

Take care, Looby

markoolo in reply to migmog

isn' Amiodarone extremely toxic to liver kidney and thyroid?


Hi migmog, thank you so much for your reply, that is exactly what I'm talking about, taking the dog for a walk, on way back i was getting worried, just felt like my heart wasn't keeping up with me. Just had Eco and 24 hr ECG not long ago and everything normal, my cardiologist said if everything ok he would refer me to a Electophysiologist about an abalation, but I've heard that many stories, it's made me very wary of having it done.


markoolo in reply to Hidden

please do if u have time tell more on the ablaton, many thanks

Hi, I was prescribed Flecainide 100mg last December and had no side effects at all, and it didn't stop my daily sessions of AF. So in February the dose was increased to 200mg per day and it stopped the AF completely. I feel great and have no side effects. Regarding warfarin, I have a CHAD score of 1 and the specialist was going to put me on it but then was told that I ride my horse regularly so decided the risk of falling off and possibly suffering a severe bleed would outway the risk of having a stroke. He said he would put me on warfarin when I have a more sedentary life style and in the mean time gave me Aspirin 75mg.

Hidden in reply to morrisdancer

Thanks for the info morrisdancer, I'm wandering if my dose may be too strong, my average episodes over a twelve month period is only around 2/3 times when I was on a beta blocker for 8years, and I was taken off that because of a slow heart beat, around 48 beats per min.


Hi, just wondering how you are doing now? I switched to flecainide 3 months ago. My a fib has not returned (knock on wood)

I have been on Flecainide 100mg twice a day for over two years. I had only ever had two episodes of AF before starting Flec( within a month of each other) prior to this; one at diagnosis and one while on bisoprolol which slowed my pulse so much they couldn't increase the dose. Since the flecainide I have had odd episodes of "weirdy" chest pains in different places and occasionally suddenly feel the need to lie down . I've always put this down to anxiety. have only had one episode of AF following a nasty viral infection in the New Year. All in all in spite of my GP saying "Well it is a dirty drug, but if it suits you fine" I'm very happy with it. have just started on warfarin too as I'm female and over 65 which gives me chads2 vasc score of two.


Hidden in reply to Bagrat

Hi Bagrat,

Thanks for your comment, as to your question , I was on warfarin for 8 years with no problems, I was taken off prior to having a gall bladder operation and put on Asprin . After the operation my doctor decided to keep me on Asprin due to my chads score , being under 65 and normal bp. Hope he was right to do that, I had an episode 3 days ago and it still worries me whether he made the right decision . Didn't worry half as much when I was on warfarin.

Sure you'll find being on Warfain fine, as long as you keep up with your INR checks.


markoolo in reply to Bagrat

OMG why is it a dirty drug please? I am on it

Bagrat in reply to markoolo

Crumbs, this is a blast from the past thread. I've now been on flex since 2011. Last September with the help of my GP I gradually reduced my dose to 50 mg twice a day which has been great. Don't panic about dirty drug as a descriptor. Many drugs have unwanted effects as well as wanted ones and flecainide is one of them. For many people like me it works a treat .For others the unwanted effects outweigh the wanted ones. No medication is perfect.


Hello Linbobs,

Like you I was initially on Sotalol and had the slow heart beat problem. But Sotalol was not effective either. I was put on Flec initially as pill-in-the-pocket for when I got AF, and then on 100 mg daily which was resonbaly effective but I still had breakthrough AF, once causing me to pass out. I had an ablation that was largely succesful, and since then I have been on 50mg of Flec daily to reduce ectopics and prevent tachycardia - I've been on Flec for probably 5 years now, have no AF, and no side effects at all. I go to the gym regularly, and can do a 20 mile country walk. Sometimes I increase the dose if I get excessive ectopics because of someting I've eaten, and at over 100mg I get slight nausea from the Flec.

But long term of Flec, absolutely no problems. But we're all different!

Take care, Chris H

Hi Linbobs,

I was put on Flecainide a few years ago and had the same results.After about 2 weeks I decided that this was not the drug for me. EP switched me to Propafenone and I took it for almost 2 years. It did somewhat tire me out for the first 2 weeks but nothing like the Flecainide. After that first two weeks I was pretty much back to normal. I also took only beta blockers for the first 9 years of AF and my attacks started with 1 or 2 per year and ended up with 1 or 2 per week over a 10 year period. The propafenone really helped to slow them back down to 1 or 2 a year until November of last year. My EP said that I would need to switch drugs again or have an ablation.

I chose the ablation which was done in Feb of this year. It is the best choice I have made. I was so afraid of having it done and now I can't figure out why. I just went to sleep and when I woke up (about 6 or 7 hours later) it was all over. I had 2 or 3 attacks in the first few weeks (which the EP said would happen) but they were so mild that I could hardly tell they were happening. My normal attack was about 6 to 10 hours long, heart rate of 175 to 185 BPM and my blood pressure would crash and bottom out. I felt like I had been hit by a truck for about 2 days after the attack. After the ablation the few attacks I had lasted about 45 mins to 1 hour, my heart rate never got above about 115 and my blood pressure stayed steady and when it stopped I had no after effects.

The procedure was so easy and I had almost no pain at all (except for being sore from laying down for a day). I was pretty tired afterwards and gained my energy back over a period of about 4 or 5 weeks.

I ran out of my propafenone about 3 or 4 weeks ago and did not renew it. I have been off my med for about 4 weeks and have not had an attack in almost 6 weeks and I now feel great.

I'm not sure what stories you have heard about the ablation. When my EP suggested it I hit the AF forums and started asking questions about it. I got so many answers from others who had it done and they were mostly positive. The only negatives were from a few who said it didn't work. I watched many videos on youtube of the procedure being done and I decided to do it.

For me the only negative is that I may have to have it done again (a touch up) in 5 to 10 years but after going through it, I would do it again in a "fast irregular" heartbeat. There are many here on this board who have recently had it done so ask questions....

I agree with you about the warfarin. I would really regret not taking it and having a stroke after an attack. I have read and heard so many stories from those who had TIA's and strokes after a Dr said "I don't think you need an anticoagulant".

Welcome to the forum and keep us updated on how it is going. Ask all you want and comment when you can....


Hidden in reply to TheStand

Hi Tim

Thanks for your comments, I will certainly give the ablation more thought.

David21 in reply to TheStand

Warfarin I am told has to be regulated constantly and alcohol intake has to be pretty constant. I was put on Apixaban 4 months ago and so far all fine. David

markoolo in reply to TheStand

appreciate your note so much!


Hi,I was diagnosed with Paroxysmal AF almost 12months to the dayThe cardiologist prescribed Asprin,Flecainide and Bisoprol.The first episode of AF was terrifying and I thought I was about to die but since on the medication the heart has calmed.

However,like yourself I find this debilitating tiredness very hard to cope with together with other symptoms I have developed ie Ringing in the ears which is very detrimental to my hearing and now have to wear aids,palpating feeling across the skull,heart beats even in my finger tips and other areas throughout my person.

Like yourself I feel utterly wacked and as a result of this I am finding I don't wont to be in company as my mind is not focused and all I can think of is getting to bed.

This give the impression to other people that I am confused as no one understands the feeling that is associated with the medication/AF

Yes,I have noticed a difference in the quality of my hair and my overall physically appearance including muscle tone also in eye problems flashing lights in front of eyes.I try not to burden friends and acquaintances with my health problems however it reflects on my self confidence like yourself and how others perceive me.Vague and disinterested I should think.Is the tiredness due to the medication or the AF or both I don't know my GP tells me the medication is doing its job by keeping the heart beat stable.

My personal belief is if the heart is not functioning and pumping adequately then there are going to be consequences ie atrophy of the artoria,lungs and kidneys..

I know I cant turn back the clock and no one lives for ever but having said that there is not much quality of life feeling so physically depleted...

Your hair looks lovely in the picture so try not to worry to much, I know its easier said then done.

Take Care,C

Terjo in reply to Hidden

Hi carom,

Sounds very familiar, one thing that gave me some respite was coming off bisoperol which was doing far more than slowing my heartbeat. I'd been really swollen internally for years and this stopped after coming off the beta blocker and I felt great for a few months but now I'm back to feeling exhausted again. The noise in my ears is very intrusive . Like you I feel I would like to turn back the clock .

Hope you feel better soon please let us know about your progress. Teresa

Hi, I was on Flecanide a few years ago, before my second, successful catheter ablation. It had no effect on my PAF and so the doctors increased the dose and two weeks later, while on remembrance day parade, I collapsed in the street. The outcome was that I had had an episone of Ventricualar Fibrillation caused by the Flecanide. I was put on Amioderone after that until the ablation.


Hidden in reply to Wiccan

Hi Samantha,

Yes I believe this is the danger of Flecainide with some people, it's a very potent drug.

markoolo in reply to Wiccan

thanks for the note, I read amoderone is very toxic to liver kidney and thyroid, you had no issue?

I was on flecinide for 15 years and I never had any problems with it. I was taken off of it recently and am taking tikosyn now.


dmac4646 in reply to albyone

Tikosyn is a new one on me , how do you find things on it compared to Flec ?

shadski in reply to dmac4646

I'm on Tikosyn. It's a rare and dangerous drug when you first go on to it. It is an anti-arrhythmic drug that doesn't slow your normal/resting heart rate. you should go to the hospital and be monitored with an EKG 24/7 for at least 3 days when you go on it, off it or change doseing. It can change a part of the EKG that can only be shown on the EKG. This change can KILL YOU if it is not caught. After 3 or 4 days the danger passes. It is more likely to occur if you have low or even low normal levels of Potassium or magnesium. When I was in the hospital, my EKG started to change after 2 1/2 days and they had to lower my dose and stay longer. Once they lowered my dose everything went back to normal.

Spoiler in reply to shadski

I was given Tykosyn in June of this year. After the second pill I had a cardiac arrest from the rhythm it caused... they did cpr and shocked my heart back to beating. Sent to emergency surgery to have a temporary pacemaker🌚

Hi, I was prescribed Flecainide when I was diagnosed with AF, but after a week I had to come off it, I was feeling very sick all the time, and my energy levels were on the floor. Then we tried beta blockers but they caused migrains, so eventually I was given a Calcium Channel Blocker called Slosem and so far so good.

Hi linbobs

I was diagnosed with paroxysmal AF about 15 years ago and placed on flecainide within 12 months. Side effects were ok to start with and the bouts of AF reduced dramatically. However after about 8 or 9 years things went down hill dramatically, with the frequency increasing to 1 every 7 to 10 days. It was then decided that an ablation would be good, but things got worse so I had another ablation and still no improvement. Further tests revealed that I had now developed a long QT syndrome caused by the flecainide. This was then stopped and I was prescribed Amiodarone and was told that this would have to stop within 6 months as the drug was so toxic. This did control the rhythm but I then had another ablation and 3 months later all drugs were stopped. At this stage I thought all was cured but here we are nearly 12 months later waiting for a trip to the Cardiologist as we are now have 2 to 3 bouts a week. but to look on the bright side I must have had at least six months without drugs and I can say it was bliss, and it does mean another day out in London it cant be all bad can it. Good Luck

I was prescribed flecanide before cardioversion it put me in sinus rythmn but gave me atrial flutter for which I then needed an ablation now after 4 cardio versions I am still no further. I have follow up appointment on Saturday for the last procedure( which lasted 48 hrs).I wonder what they are going to offer this time?. I say, Beware of Flecanide!!

HI, I have been taking Flecainide for about 12 months, 50mg twice per day. The Flecainide replaced Amiodarone. I am also on Diltiazem (90mg twice a day) and Metoprolol (50mg twice per day). This combination is very effective at controlling AF and I have not had a bout since being on Flecainide. I do not suffer any side effects except chronic tiredness. I can function normally in terms of going to work, working in an office all day etc but any physical exercise is a no-no. I tried doing some digging in the garden last weekend. I lasted about 10 minutes and needed to sit down for two hours after to recover. I believe Flecainide is the cause but I guess it might be one of the other drugs. I had an ablation three months ago but suffered a bout about four days later. The doctor told me to stop taking all of the drugs immediately after the ablation. Not a good idea in hindsight. I have been told this week to stop taking Flecainide and if there is no recurrence then to stop the other two as well.I have decided to cut down the doses slowly instead i.e. 25mg twice/day instead, so we'll see how it goes. Fingers crossed.

Hidden in reply to chuckle

Hi, Chuckle,

It sounds to me like the Flecainide , only because its the effect it has on me.

Couldn't comment on the other drugs as I haven't taken them.

I tried like you to cut down to 25mg twice a day, I no longer had any dizzy spells, but I kept feeling a little panicky so I went back then to the original dose. Decided to wait until I saw my doctor to see what he had to say.

Hi Linbobs i had atrial flutter for years was put on a drug of which i dont remember the name of which did not work so was put on flecainide this was very effective for a while but then attacks increased so had an ablation which cured the flutter but while doing this they discovered the af the attacks of this became very regular and debillitating and was dragging me down , i was offered an ablation of this which i decided to have ,it was a success for 4 weeks then symptoms returned regularly , my bisoprosol was increased to 3.75 mg ands my flecainide to 300mg a day , the symptoms are still occuring on a regular basis and make me feel so unwell , my cosultant has said another ablation is needed which i have agreed to as cannot put up with the severe symptoms of af , anyway its only since reading the answers to your question on here that its probably the flecainide and bisoprosol that are to blame for some of them ,side affects that is , one thing for sure mind the af symptoms are awfull and scary at times so think about the having the ablation then touch wood no more flecainide , thats what i hope for after this one , regards

Hidden in reply to lepaul

Hi lepaul, thanks for your reply , I will certainly consider the ablation, especially after the latest episode last Monday , like tou say very scary.

Hope everything goes well for you after your next ablation , take care


Hi linbobs.

I've been on Flecainde for about 6 years, withthe dose increasing from 50mgs twice a day to 150mgs twice a day which I've been on for over 4 years. i have no side effects at all. I'm almost AF free. I've had 2 forty-minute episodes in the last 15 months, bioth just before I was going to bed in the evening.

I was on Amiodorone for 11 months but it didn't reduce episodes and I had chest and arm pains and feelings of panic when on it.

I've been on Warfarin for the last 2 months (previously 300mg aspirin). .

dmac4646 in reply to Thomas45

out of interest what time of day do you take the Flecanaide

Thomas45 in reply to dmac4646

Around 11am and 11pm. Sometimes I forget the morning one, so around 11am means up to 2pm. I have 3 other tablets to take arounfd 11pm (a statin, warfarin, and doxazosin) so don't often forget that one.

dmac4646 in reply to Thomas45

thats interesting , I think it lasts about 12 hours in the system so that would appear to give you good coverage,

I have been on and off flecanide since 1992 I had a bad INR 5.6 which was put down to the flecanide. I am asthmatic and with Lung Fibrosis and Pleurisy so am very limited to what they can give me. I am on sotalol twice a day was three but my fingers went blue and Digoxin once a day. I have been on bisoprosol / Amiodarone.

I had my first catheter ablation in April of 2014 to correct atrial flutter/fib. I had the second one on May 7, 2015 to complete the process due to paroxysmal a-fib that returned after the first one. After the second procedure I was prescribed flecainide 100mg 2x/day. I also got 120mg diltiazem that was reduced to 30mg 2x/day. Due to worsening side effects - mostly dizziness and fatigue - I stopped the diltiazem on June 4 and the flecainide on June 13. It is now four weeks after stopping flecainide and I continue to experience dizziness and fatigue to the point of passing out for brief periods, which has happened three times in the past week. Other side effects include mild numbness in hands and feet, wheezing, shortness of breath, shaky hands, occasional chills and tremors, a rash, no stamina whatsoever, and subtle changes in vision. As an active, athletic 65-year-old male with a resting heartbeat of 60 or less, this has been truly debilitating.

My symptoms were fairly moderate - up to 6 or 7 on a scale of 1-10 - until five days after stopping flecainide. Then they suddenly worsened, regularly reaching 8-9 and a few times hitting 10, which I define as being so utterly exhausted as to lose consciousness.

I find it quite interesting that my symptoms go away at night and return within one or two hours after getting up in the morning.

The last two days' symptoms have been quite mild and have lasted only a few hours each day. I hope it's a trend.

Edit July 14: It was not a trend. The dizziness and fatigue have decreased in intensity but tiredness and involuntary naps (i.e., passing out) continue.

I had alot of trouble when I first was put on flecanide. My vision was blurry from my left eye and the left side of my lip and face was partially numb. I was taking 100 mg twice a day. The dr changed me to 150...50 three times a day. The symptoms went away. It has been a miracle drug for me. I had an unsuccessful ablation and am now back on flecanide. AF can work on a persons nervous system. I've been in the hospital several times in the past yr. I'd give flecanide a chance. You may have to cut down on your dosage. Good luck with it.

markoolo in reply to boge

nervous system? please tell more

I was on Flecanide for 9 years,but began getting problems taking it. So stopped it,at the moment I don't take anything

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