Clinical information
Common uses
- prevent paroxysmal supraventricular tachycardia
- prevent paroxysmal atrial fibrillation or flutter
- prevent life-threatening ventricular tachycardia
Common side effects
- dizziness
- blurred vision or other visual disturbance
- shortness of breath
- headache
- feeling sick
Cautions
- boxed warning: raised death risk after heart attack — avoid then
- can cause new or worse heart rhythm problems
- not recommended for chronic atrial fibrillation
- ventricular tachycardia treatment is started in hospital
Interactions
- digoxin (levels rise)
- beta blockers such as propranolol (additive heart effects)
- amiodarone (can double flecainide levels)
- cimetidine (raises flecainide levels)
- quinidine (raises flecainide levels)
- verapamil or disopyramide (avoid combining)
Pregnancy: only if benefit justifies risk to the baby
Reference information, not medical advice — always follow your doctor or pharmacist. Source: DailyMed, dailymed.nlm.nih.gov, Flecainide acetate label, setid 74c1eb2a-a37f-4f33-86bf-51e0d1d0c2bc (accessed 2026-08-16)