Muscle Weakness On Flecainide

Hi Friends, new member here. On Monday, after 6 wonderful years of perfect rhythm, my ablation failed, and afib came back. My Dr. put me on Flecainide, Diltiazem, and Xarelto. My afib is gone, but now I have insomnia, and muscle weakness. It's the weakness I'm worried about. I went to the gym yesterday, and couldn't do my normal routine. The weird thing was, I would be doing a set of exercise, and--rather than a gradual onset of weakness--I simply could not do another repetition. It was like a light switch had been turned off. Has anyone else experienced this? Thanks!

I doubt it's the flecainide. It's more likely the diltiazem. Diltiazem is known to cause fatigue like that. You didn't mention the dosage, but lowering it would probably help.

And not that it really matters, but your ablation didn't fail. An ablation that lasts one year is considered successful, and there's no way for that success to be undone. What happened is your afib progressed, which is what afib does. A new source of afib developed outside the areas isolated by your ablation, so the afib is back. Finding and ablating that new source is definitely possible, and should be a shorter, easier procedure than the first one, but doing that requires a top notch EP with extensive experience. It's not a job for an average EP.

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Howenow
Has anyone else experienced this?

It does show up on this page as a rare flec side effect: "unusual tiredness or weakness." It is also a less common side effect for Diltiazem.

I've used flec on-demand to convert for 17 years but only one month of that time was chronic usage. I've not experienced this issue. As I take a loading dose to convert, I usually wait 24 hours (which is two half-lives) before I do anything really strenuous. I do this as I don't take any rate control with it and want to minimize any proarrhythmic effects of the med.

Yeah, but fatigue shows up as a side effect of just about every drug on the planet. I've taken diltiazem and it caused significant fatigue for me. Not as bad as beta blockers, but enough to reduce my cycling abilities. Flecainide did not.

Many Thanks, Carey!

Howenow:

Can you list the dosages of your Meds? And how long have you been on the Flec and Diltiazem?
How is your HR and BP compared to normal?
I think it is possible it is the Flec, are you "out of breath" when this occurs?

Sure thing! I'm on two daily doses of 150mg. of the Flecainide; 240mg. of the Diltiazem, and 20 mg. of the Xarelto. My heart rate is always a little elevated--about 88 BPM. My BP flucuates, but I'm usually a little higher than optimal. I've been on these meds since Monday. No shortness of breath while it's happened.

You're on the maximum dosages of both drugs. Talk to your EP and ask about cutting the dosages down because of the side effects. I would ask to cut both in half, and then adjust later if needed.

Many Thanks, Carey!

Yes high doses your on. I have taken both these drugs repeatedly, but never at this high of dosing. Unless your in severe distress, why does this EP need to start you out on such high dosages? Are you 7 ft tall and weigh 600 pounds? Start with a lower dose of the Flecainide as Carey said, and titrate up if you need to. Same thing with the Diltiazem. Are you on 240mg twice a day equaling 480mg? or 240mg total for a day? I never got much over 200mg/day of Flecainide and 180mg of Diltiazem, due to effects/side effects.

Also check the formulation of Diltiazem, they have an immediate release, 12-hour release, and 24-hour release. Make sure you are are on the 12-hour or 24-hour release if taken twice daily, or the 24-hour release if taken once daily.

Hope this helps.



Edited 6 time(s). Last edit at 10/10/2021 12:57AM by The Anti-Fib.

Personally i hated Diltalizem! I used it during flutter episodes back in march then in may. A week to 10 days ea time. First i took 60 mg 3-4 times a day then was switched to the 240 slow release. Felt tired weak lethargic. Following my 8/6 Natale ablation i take Propananol 20/20 and eliquis 5/5. None of the previous side effects now

Sorry to hear you are again dealing with rhythm issue.
I take Flec, but don't get weakness.

Tibbar