Flecainide with or without bisoprolol

Another topic recently spinned off onto this topic. healthunlocked.com/afassoci... The question merits a wider discussion. By bisoprolol I include beta-blockers or alternative calcium channel blockers.

Now, if you are comfortable with taking advice from doctors, then go with that. But some of us feel more comfortable when we directly interact with doctors, and come to a joint decision.

It has been said that Flecainide MUST be taken with bisoprolol. drugs.com/ppa/flecainide.html and this article talks about initiation and continuance. Right now I will leave aside the initiation question. For the question of continuance, the point seems to be that maybe the ventricular rate will be increased, which blockers counteract.

There is also the assertion on safety that Flecainide can double the repeat rate of a heart attack. I am routinely suspicious of this argument, since, it is not the percentage increase that counts, it is the absolute figures. When absolute figures are missing, then someone is hiding something. When the absolute rate is less than 0.1% then it can probably be ignored since other factors swamp the estimation.

Looking for recent review articles on this subject.

1. medscape.com/viewarticle/73...

there is no mention of blockers.

2. 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation. I quote concerning the possible effect of Flec on the ventricular rate: "Control of the ventricular rate using a beta blocker or nondihydropyridine calcium channel

antagonist is recommended for patients with paroxysmal, persistent, or permanent AF (260-262). (Level of Evidence: B)". Note the level of evidence. This is B, which looks impressive but it is not. It is "Data derived from a single randomized trial or nonrandomized studies". At this point, the vaguely possible benefits may well be exceeded by the negatives. Remembering that is it well known in medicine, that half such research papers are probably wrong, and you get a question to think about, no where near strong evidence.

3. Review Article. 2012. Safety of Flecainide. Tamargo, Capucci and Mabo. Drug Safety 35(4):273-289. This does not mention betablockers as a useful extra. On the contrary, section 4.3.2 says, and I quote for those who do not have access to this article: "When used to prevent the recurrence of PAF flecainide has been shown to have a good safety profile". The only significant warning is to watch the Potassium levels in your blood. + the usual list of contraindications.

Section 5.2 warns AGAINST the use of betablockers with Flecainide. "The co-administration of flecainide and pro-

pranolol increased the plasma levels of both drugs by 25% compared with control values, which may exert an additive negative inotropic effect and prolong the PR interval".

So, there you are. I hope this is interesting to some people. At least, for me, it renders highly questionable the assertion that both MUST be taken together, while leaving open that there are, sometimes, in a minority of cases, some good reasons.

11 Replies

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  • I didn't reach review article 2012, or Section 5.2.

    I was already asleep zzzz

  • Very interesting post, particularly the reference to Safety of Flecainide which I couldn't access fully.

    I take Flecainide and Bisoprolol, have short runs of AFlutter which my EP says are caused by Flecainide and I asked him if Bisoprolol could be used as a PIP. EP said that could be dangerous as, without the beta blocker, the conduction rate of these runs could be high. I notice the same comment with explanation in the second link you give and I saw another article which detailed the electro mechanisms which can cause this to happen.

    The quote from section 5.2 I have saved for discussion (and clarification) - eg what is the effect of prolonging the PR interval?

    Thank you for posting this - I would love to be rid of Bisoprolol but not at the risk of 1:1 conduction of AFlutter.

  • It is usually very important to take a beta blocker, verapamil or diltiazem when you are taking flecainide. This isn't a vague benefit but something that is recommended by most electrophysiologists.

    The reason is that flecainide can converts AF (irregular and chaotic) into atrial flutter (regular and rapid). The flecainide will slow the rate of the atrial flutter but not the rate of the ventricle. This can lead to very rapid and dangerous heart rates. Flecainide can also affect the ventricles in other ways to make the problem worse.

    So flecainide usually needs to be taken with a drug that can control the ventricular rate. However there are exceptions to this so don't be alarmed if this hasn't been recommended for you.

  • More than once I have had explained to me that since I am on Warfarin for life, if the heart goes crazy, I am protected, and I have time to get to a cardiologist. Thanks though for the clear explanation.

  • The other fact cardiologists say about me is that since I have been on Flec alone for over 5 years in the past, I am highly unlikely, unless something else is discovered, to have the feared problem.

  • Interesting stuff. I've been taking Flecainide for 5 years, initially 200mg and more latterly 300mg. I started it after having a second cardioversion and my EP was insistent that the initial dose was administered in hospital post CV. Initially he also insisted that I took a beta-blocker which I did for about three months, from memory. After that he agreed that I could stop the beta-blocker. I have a bad time on beta-blockers so did not want to be taking them permanently. I also have a relatively low resting heart rate, 60bpm, and when I get an occasional episode of AF my rate rarely goes above 130bpm and I don't have any other contributing risk factors.

    As always, medical opinion differs between doctors as does risk profile between patients. This condition is a challenge as we all know and is about managing risk against quality of life. Having an informed and educated discussion with your EP who knows your complete medical history is at the centre of this process.

  • Another good question to ask is, since I have now been on Flec alone for this length of time, how likely is it that the other dangerous problems will develop? With other similar questions, my cardiologists have all said, unlikely, therefore no more need for tests!

  • I should have said when my flec dose was upped I had a blood test after a couple of weeks to check the state of my liver. Apparently I still have one and I was given the OK to continue.

  • That too is interesting. Almost every major drug I have been prescribed over the years has some other tests that need to be done, and they have NOT been. It has either been for me to find out, or the casual remark of my GP asking if I knew about it (therefore needed to remind/ask), or for me to check in the BNF. Even in the BNF sometimes this information is hidden, or simply not there, or the frequency is too far apart. Classic case: Amiodarone. Retest after 6 months for thyroid etc. I am glad I insisted on it after 3 months.

    This is an important, often neglected question to ask.

  • We can read and consider. We can worry and compare but in reality there has to be an element of doctors know best. This is an old fashioned view I know and I am not saying we should mindlessly accept what our HCPs say BUT they have had years of training and experience. They are taught how to interpret research and sift the wheat from the chaff. We can play an important part in our care and ongoing health by accurately reporting our response to their ministrations.

    A colleague was once asked how we could ensure the ubiquitous "informed consent"in this instance regarding chemotherapy for cancer. Her reply was "Send each patient on a six month course"

  • Thankyou for some VERY helpful comments. One of the principles I try to follow, and sadly fail so often, is to understand a different viewpoint in full, before going on to interact with it and maybe challenge it. The posts here have helped towards that aim.

    Part of the probing though is to pinpoint exactly what the concern is, what the quality of evidence is for that concern, and to try and nuance it: under what circumstances is the advice obligatory and why? In the end, I know it is a balance of severity of the consequences for a given level of risk, against a similar assessment of other positions.

    I have learned over the years NOT to trust any doctor who says, "I know, trust me". I am more likely to trust someone, even less competent, who is able to engage with me as to detailed reasons, and together, as a team, we come to a conclusion we both agree with. My approach is I think supported by the academic research into how often experts are right, compared to the educated layman. Experts are wrong as often as educated laymen, and error is minimised when two people share their expertise. And the layman certainly has an expertise, as many a doctor has told me, and told me to develop. The main difference is my expertise is limted only to me. It is encouraging that patient.co.uk website includes information destined for health professionals, but available to all.

    The doctor performs an excellent role in checking through the list of 'definitely a serious problem' -- probably rare, but need to be eliminated. My experience with doctors is that I have to remind them of some of these checks to do. Hence, I go to interviews with a prioritised checklist of questions well aware that my list can swing the discussion one way or the other. The doctor can usually interpret data such as the ECG and echo and present and explain the findings to me. But I do not trust any doctor who cannot or is not willing to explain.

    And, yes, I have seen three cardiologists in the last 10 years, and none of them has ever even mentioned I must have bisoprolol. That is said more to reassure those who think I am acting too independently!

    Apart from the safety, there is one missing element in these papers. For a small minority of people, I think I am right in saying, Due to stress, the irregularities increase. To control the irregularities, the rate increases, and some type of tachycardia starts. If all goes well, this resets the heart, and the tachycardia suddenly stops. Sometimes the tachycardia gets stuck, and in the ensuing battle, it becomes irregular and fast. At this point, the correct PIP is ONLY flecainide, because the problem is the irregularities, and a fast heart rate is doing its job. To include bisoprolol, the full PIP would be counterproductive.

    That is how my AF started. I had supraventricular tachycardia which would not stop. I went to emergency the next day, they did an ECG, checked I was on warfarin, said it was not dangerous and could go to work, and see your cardiologist in two days time! He promptly ordered some key tests which eliminated rare but dangerous problems, and put me on Flec+biso, in the hope it would stop. It did not. Knowing what I know now, I should have been started on Flec alone when at emergency, then sent to work. [possible without initiation in hospital as I had already had Flec for several years, therefore had known tolerance].

    The most stressful part of the next three months was becoming familiar with AF, different opinions etc so that I could meaningfully interact with doctors. Once I knew the terrain, I relaxed more and gained confidence in my interviews with the doctor. Sadly, this was not acceptable with one doctor (private) who stiffened up at one point and told me that if I wanted his help then no more discussion or debate. At least I had the freedom then to change my doctor.

    So, I really appreciate this forum where I can have my reasoning checked and I can learn some more.

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