AF Association

Flecainide side effects?

My husband took 300mg flecainide and 5mg bisoprolol a few days ago when he had AF. An hour after taking them he felt ill with blurred vision and dizziness, minutes later he vomited and had a fit (this only lasted a short time and when he came round he had no recollection of it). He was taken to hospital and they found that his blood pressure was very low 80/60 but his ecg was fine. He was monitored overnight and his heart rate was normal. The doctor thinks perhaps it could have been a reaction to either the flecainide or bisoprolol and has taken him off both of these medications. This was only the second time he'd taken flecainide (he had no problems the first time) but he had previously been on bisoprolol for several months without any side effects apart from slow pulse and tiredness.

Has anyone else had similar problems with flecainide or have any advice please?

5 Replies

Hi There i 'm prescribed 300mg of Flec at onset of my Afib, I do experience a little light headidness and a bit of blurry vision within the first hour but then that goes. I don't tend to worry to much about it as it states that it is what may happen.


Hi Lotusbuddah

I'm surprised he was on both bisoprolol and flecainide at the same time, I have been on both at different times and they both had bad effects so I'm not surprised your husband was poorly. Bisoprolol can lower blood pressure too much for some and flecainide can cause serious visual disturbances. I hope he's OK now

All the best



I used to be on both bisoprolol and flac 300 mg daily for two month , I was Ill most of the time , very tired and week dizzy , strong heart beats shaking all my body , and my pressure was low 90/35

I stopped the flac a week ago and I felt a lot better

My doctor advised me to take three tablets of flac only when I get AF attack but really I'm worried since I believe that such symptoms such as your husband may accrue


I had a bad experience with flecainide last week. Horrible drug, cause my symptoms to get worse plus gave me anxiety and awful paranoia.

I was cautioned NOT to take flecainide with bisoprolol as the two work against each other.

I have read about people on a very low dose bisoprolol taking flecainide but not regular doses.


Fleicainide either works for you or doesn't, it really suits me, but it seems others cannot tolerate it. If it works for you its meant to be the best drug to take, but that is just what i have been told. 300 mg of this drug seems a lot in one go tho. Plus the other stuff.

I hope the event hasn't halted your husbands positivity in managing this condition.


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