Flecainide
"I am a reasonably well controlled insulin dependant diabetic. I was put onto flecainide as I was unable to have an atrial ablation and had reacted badly to both beta blockers and calcium blockers. Within 24 hrs of taking a dosage of 30 g , twice, I lost all control of my blood sugars.  I stopped taking flecainide within 48 hrs of the start due to out of control blood reads ie excessively high. 2 days further down the line I still have no control of my blood sugars and have so trebled the amount of insulin I would normally take, eg 14 at breakfast to 8( plus an additional 8 units mid morning). 18 at lunch compared to a usual 8 units as examples.  My diet has currently very little carbs in it as I attempt to get things back under control."