How much Flec is too much?

I take 250 mg. flec when go into an episode. Daily dose has never worked for me. P-in-P works best to stop an episode (these days anyway) in less than 2 hrs. However, I had an episode and it stopped but in about 15 hrs. woke up in the middle of the night in another episode. This is unusual. Taking another dose of Flec is out of the question so close due to its toxicity. Apparently Flec stays in your system up to four days. The episode is "mild" so I am now waiting.
My question: How soon could I feasibly take another 250 mg. dose???
Thanks,
Ritva

24 hours period of taking a max dose of 200mg if you weigh less than 154 pounds and 300mg if you weigh more than 154 pounds.

So if you get an episode after 15 hours you have to wait the remaining 9 hours before taking another PIP dose.

You mentioned you take 250mg…I hope you qualify for the weight dosing of >154 pounds.
[www.afibbers.org]



Edited 1 time(s). Last edit at 10/15/2021 01:31PM by susan.d.

Quote
Ritva
Apparently Flec stays in your system up to four days.

The quoted half life of flec is 12 hours. This could vary by individual. So after 24 hours, the flecainide in your system would be half of a half or 25%. This is very much a generalization.

"5.2 Pharmacokinetic properties Source
Following oral administration, the absorption of flecainide acetate is almost complete (90%), and peak plasma concentration occurs after 3-4 hours. It is weakly plasma bound (40%). In patients, 200 to 600 mg flecainide daily produced plasma concentrations within the therapeutic range of 200-1000 µ g/L. Protein binding of flecainide is within the range 32 to 58%. Oral absorption does not appear to be affected by either food or antacids.

In healthy subjects the plasma half-life of flecainide acetate is 12-13 hours after a single oral dose. However, the plasma half-life is prolonged after multiple oral doses (16 hours) and in patients with ventricular arrhythmia's (20 hours).

After oral absorption flecainide acetate is metabolised by the liver and undergoes extensive biotransformation. Approximately 86% of a dose is excreted in the urine, 27% as unchanged flecainide acetate and 59% as metabolites. The two major urinary metabolites are meta-O-dealkylated flecainide acetate and meta-O-dealkylated lactam of flecainide acetate. (Only 5% of an oral dose is excreted in the faeces). These metabolites have no clinically significant antiarrhythmic effects

The rate of flecainide acetate elimination from plasma is reduced in the presence of renal failure, liver disease and congestive heart failure. The urinary excretion of flecainide acetate is reduced in patients with renal failure and significantly so in patients with severe renal failure."



Edited 1 time(s). Last edit at 10/15/2021 09:26PM by GeorgeN.

I decided to wait it out. Actually went back to sleep. Back to sinus spontaneously at 9 am. the next morning so approximately 9 hrs.

Since 2008 (13 years ago), after a series of 2-4 hour episodes once a week or so, the Dr put me on 100m of Flec twice a day. And put in a pacemaker (I w 61 at the time)
I have been on Flec ever since.
During the first 5-10 years after being on Flec daily, I might get a brief 2-4 hour episode one to 4 times a year.
The last 2 years I have had no episodes, so on my own, I cut back the Flec to 50 mg in morning and 100 mg at night.
Maybe I should cut back to 50 and 50 or trying just stopping and see what happens, but in years past when I get my 2 hour episode, I am shot for a week ie very symptomatic.
What is long term effect of Flec on you?
I am 75, 150 lb non smoking male in reasonable shape.
Thai every one involved with s forum



Edited 2 time(s). Last edit at 10/20/2021 01:06PM by tibbar.

Hi tibbar,

Flec can lose its efficacy over time, which may be happening to you. Also, your disease may be progressing, making it more difficult for flec to control the afib. In any case, a chat with your EP about your options (different med, or perhaps ablation) may be in order. It seems was initially effective, with your episode frequency dropping from ~ once a week to ~ 1-4 episodes a year. You could see what happens reducing or eliminating your flec, but your episode frequency would be unlikely to get better, IMO. As 200 mg/day is the max for someone your weight, increasing flec is not an option.

Tibbar,
Do you take any beta blocker with the fleck?
If not I would take bisoprolol 2.5 mg in the evening after approval from your cardio or ep.

George,
Thanks for taking the time to reply.
I meant to type that I have had no episodes in the last 2 years (the pacemaker records them).

Thanks,Tibbar

Ben,
Thanks for replying.
I corrected my original message (see above).
I take 25 mg of Metroprol, 2.5 mg of Warafin, 30 mg of Lisinioril, 20 mg of Lovastatn

I take a vitamin, CQ10, and Tumeric.

Thanks,
Tibbar

Quote
tibbar
I meant to type that I have had no episodes in the last 2 years (the pacemaker records them).

In that case, then a trial of reducing or eliminating flec may make some sense. Because flec can lose its effectiveness over time, it makes sense to use the lowest possible dose that is effective. If you could go to no flec and use it only on demand if/when you have an episode, that might reduce the potential loss of effectiveness.

Quote
GeorgeN

I meant to type that I have had no episodes in the last 2 years (the pacemaker records them).


In that case, then a trial of reducing or eliminating flec may make some sense. Because flec can lose its effectiveness over time, it makes sense to use the lowest possible dose that is effective. If you could go to no flec and use it only on demand if/when you have an episode, that might reduce the potential loss of effectiveness.

I tried that experiment. I lost weight and experimented going from 100mg/ twice a day (200mg in 24 hours) to 75mg twice a day (150mg in 24 hours) and my afib returned worst. I went back to 200mg/24 hrs like I had for 15-16 years and it never returned to pre experimenting success. That’s when I tried pip and unknown that 200mg is the maximum dose if one weighs less than 154 pounds, I ended up in the icu with a flecainide overdose taking 300mg in 24 hours..

Moral-don’t experiment on your own. Flecainide is a black box drug.