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Flecainide

Definition, side effects & dosage

What is Flecainide?

Flecainide is an antiarrhythmic medication can works to slow nerve impulses in the heart and normalize its rhythm. It is most commonly used to treat serious conditions like paroxysmal tachycardia (PSVT), paroxysmal atrial fibrillation (PAF), and sustained ventricular tachycardia (sustained VT).

Flecainide Side Effects & Risks

As with most medications, there are side effects and risks associated with taking flecainide. This is not a complete list. If you experience any other symptoms, contact your doctor.

Common side effects

Common side effects of flecainide include difficult or labored breathing, dizziness, fainting, lightheadedness, irregular heartbeat, shortness of breath, chest tightness, and wheezing.

Uncommon side effects

Uncommon side effects of flecainide include chest pain, fainting, feeling of warmth, fever, increased sweating, paralysis, shakiness in extremities, swelling of feet or legs, trembling of hands or feet, skin redness, loss of muscle control, and burning or tingling feelings.

Rare side effects

The following side effects are rarely experienced by patients taking flecainide.

  • Arm, back, or jaw pain
  • Black, tarry stools
  • Bleeding gums
  • Blood in the urine or stools
  • Blurred vision
  • Chest discomfort
  • Chest tightness or heaviness
  • Chills
  • Confusion
  • Convulsions
  • Cough
  • Decrease in the frequency of urination
  • Decrease in urine volume
  • Difficulty in passing urine (dribbling)
  • Difficulty with breathing
  • Dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • Frequent urination
  • General feeling of discomfort or illness
  • Headache
  • Increased volume of pale, dilute urine
  • Nausea
  • Nervousness
  • Noisy breathing
  • Painful or difficult urination
  • Pinpoint red spots on the skin
  • Pounding in the ears
  • Sensation of pins and needles
  • Slow or fast heartbeat
  • Sore throat
  • Sores, ulcers, or white spots on the lips or in the mouth
  • Stabbing pain
  • Sweating
  • Swollen glands
  • Thickening of bronchial secretions
  • Troubled breathing
  • Unusual bleeding or bruising
  • Unusual tiredness or weakness
  • Yellow eyes or skin

Flecainide Dosage & Available Forms

Flecainide is only available as a 50mg, 100mg, or 150mg tablet. Typical dosage for an adult is between 50 to 400 mg per day. For children, the dose will be set based on body size and weight. The starting dose for infants under 6 months is 50mg per square meter per day; for children over 6 months, the dose is 100mg per square meter per day. Doses are typically divided into two or three equal doses per day for children.

It can be taken with or without food, and it will often take about a week to see the full effects of flecainide.

Symptoms of flecainide overdose include nausea, vomiting, slow heart rate, seizure, and fainting. If you think you may have overdosed, seek medical attention immediately.

Do Not Take

Patients should avoid taking flecainide if any of the following statements are true.

Allergic reactions

Do not take flecainide if you are allergic to flecainide or any ingredient in the formulation or packaging.

Interactions and contraindications

Flecainide can interact with several other medications including digoxin, bepridil, sparfloxacin, thioridazine, piperaquine, and cisapride.

Children and young adults

Safety and efficacy have not been established in the pediatric population. However, in very severe cases, doctors may believe the benefits outweigh the risks.

Pregnancy and lactation

Studies show that flecainide poses minimal risk to infants via breastfeeding.

Medical history

Make sure to tell your doctor if you have a history of AV block, bundle branch block, heart disease, heart attack, kidney disease, electrolyte imbalance, liver disease, chronic atrial fibrillation, cardiogenic shock, congestive heart failure, sick sinus syndrome, or pacemaker use.

Abrupt withdrawal

If you have been taking flecainide for several weeks, you should not stop it cold turkey. Your doctor can help you gradually wean off of the medication over time.