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What does it do?

Flecainide is used to treat and prevent irregular heartbeats.

How should you take it?

Take flecainide regularly at the same time every day. Take with a glass of water.
Swallow controlled release (CR) flecainide tablets whole. Do not crush or chew them.

What if you forget a dose?

Take the missed dose as soon as possible. If it is close to the time for your next dose, skip the missed dose and carry on as normal. Do not take two doses at the same time.

Can you take other medicines?

Flecainide can react with many medicines, sometimes with severe results.

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products or recreational drugs.

What side effects might you notice?

Side EffectsRecommended action

Change in heartbeat, chest pain, fainting

Increased risk of infection - symptoms may include: fever, chills, sore throat, aches and pains, tiredness, pain when peeing, mouth ulcers

Easy/unusual bruising or bleeding

Tell your doctor immediately

Changes in vision

Tingling or numbness

Loss of co-ordination/walking or handwriting problems, tremor

Swollen feet or legs, short of breath

Tell your doctor

Nausea, vomiting, constipation or diarrhoea, abdominal pain, change of appetite

Headache, dizziness

Ringing in the ears

Trouble sleeping, anxiety, low mood

Muscle weakness

Tell your doctor if troublesome

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Tell your doctor if you have kidney, liver, eye or other heart problems.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
  • Smoking may change the effect of flecainide - discuss with your doctor.
  • Flecainide can impair your ability to do tasks such as driving or using machines. Alcohol makes this worse. Discuss your risk with your health professional. (search NZTA - Are you safe to drive?)

This leaflet contains important, but not all, information about this medicine.

Prepared by the PILs Committee at Christchurch Hospital, Canterbury District Health Board, New Zealand. January 2020

For more general information about this sheet and its contents, see: What does a My Medicines sheet cover?

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About My Medicines

My Medicines Patient Information Leaflets (PILs) contain important, but not all, information about the medicines they describe.

For more information about the sheets, see: What does a My Medicines sheet cover?

My Medicines is developed by a team at the Canterbury District Health Board. Our team is made up of doctors, pharmacists, and a non-medical person to help us keep to plain language. We also discuss our information with specialist health professionals or groups when needed