Just wondering what side effects people have experience from flecainide? I started 50 mg twice per day one week ago. I began having some visual disturbance, floaters, flashing light in my left eye and I'm so very tired and achy. Anyone else? Just wondering if symptoms will fade as my body gets use to the drug. I've had paf since 2010, 2 ablations, and af free after second ablation for 17 months, began having af episodes again in May. I was on rhythmol but doc took me off and started flecainide last week.