Indications
Flecainide Acetate is an antiarrhythmic medicine, meaning it helps control abnormal heart rhythms. It is used to prevent and treat certain fast heart rhythms in people whose heart structure is otherwise normal, including paroxysmal atrial fibrillation or flutter (episodes of a fast, irregular heartbeat starting in the upper chambers), supraventricular tachycardias such as AV nodal re-entry and Wolff-Parkinson-White syndrome, and some serious ventricular arrhythmias under specialist care.
How It Works
Flecainide blocks sodium channels in heart muscle cells. This slows the speed at which electrical signals travel through the heart, which can stop abnormal electrical circuits from forming and help the heart keep a steady, normal rhythm.
Dosage and Administration
Treatment is usually started by a heart specialist, often with heart tracing (ECG) checks. Adults: a common starting dose is 50 mg twice daily, adjusted by the doctor according to response; most adults do not need more than 300 mg a day. Some people are prescribed a single dose to take only when an episode starts (“pill in the pocket”), exactly as the specialist directs. Take it at the same times each day, with or without food. Do not change the dose or stop without medical advice. Lower doses are needed in kidney or liver disease, as prescribed.
Interactions
- Amiodarone: raises Flecainide levels; the Flecainide dose is usually halved.
- Digoxin: Flecainide can raise Digoxin levels.
- Beta blockers (such as Propranolol or Metoprolol), Verapamil, Diltiazem and Disopyramide: may add to the heart-slowing and weakening effects.
- Quinidine, Fluoxetine, Paroxetine, Bupropion, Terbinafine, Ritonavir and some other medicines raise Flecainide levels.
- Other medicines that affect heart rhythm, some antimalarials (such as Quinine) and tricyclic antidepressants increase the risk of rhythm problems.
- Diuretics that lower potassium or magnesium can increase risk; levels should be corrected.
Contraindications
- Heart failure or poor pumping function of the heart.
- Previous heart attack, especially with irregular heartbeats from the lower chambers.
- Structural heart disease, such as significant valve disease or heart muscle thickening, unless a specialist decides otherwise.
- Heart block or sick sinus syndrome without a working pacemaker.
- Cardiogenic shock or Brugada syndrome.
- Long-standing atrial fibrillation where restoring normal rhythm is not planned.
- Allergy to Flecainide.
Side Effects
Common: dizziness, light-headedness, blurred or double vision, headache, nausea, tiredness, tremor and shortness of breath. Flecainide can sometimes cause new or worse irregular heartbeats and can weaken heart pumping. Rarely it affects the liver or blood counts.
Get urgent medical help if you faint, have a very fast, very slow or irregular heartbeat, chest pain, new or worse breathlessness or ankle swelling, yellowing of the skin or eyes, or signs of a severe allergic reaction.
Pregnancy and Lactation
Use in pregnancy only if the doctor decides it is clearly needed; it is sometimes used under specialist care to treat fast heart rhythms in the unborn baby. Flecainide passes into breast milk; your doctor will decide whether breastfeeding is suitable.
Precautions and Warnings
- Regular ECGs and sometimes blood level tests are needed, especially when starting or changing the dose.
- Potassium and magnesium levels should be normal before and during treatment.
- In atrial flutter it may speed the heart rate, so a rate-controlling medicine (such as a beta blocker) is often given as well.
- People with pacemakers may need the device checked.
- Dizziness or vision changes may affect driving.
Overdose
Overdose is very dangerous and can cause slow or irregular heartbeat, very low blood pressure, seizures and cardiac arrest. Go to the nearest hospital emergency department immediately, even if you feel well, and take the pack with you.
Therapeutic Class
Class IC antiarrhythmic.
Storage
Store below 30°C in a dry place, away from light and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.