In the U.S.—

In Canada—

• Antiarrhythmic

Flecainide ( FLEK-a-nide) belongs to the group of medicines known as antiarrhythmics. It is used to correct irregular heartbeats to a normal rhythm.

Flecainide produces its helpful effects by slowing nerve impulses in the heart and making the heart tissue less sensitive.

There is a chance that flecainide may cause new or make worse existing heart rhythm problems when it is used. Since it has been shown to cause severe problems in some patients, it is only used to treat serious heart rhythm problems. Discuss this possible effect with your doctor.

This medicine is available only with your doctor's prescription, in the following dosage form:

Oral
• Tablets (U.S. and Canada)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For flecainide, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to flecainide, lidocaine, tocainide, or anesthetics. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Flecainide has not been studied in pregnant women. However, studies in one kind of rabbit given about 4 times the usual human dose have shown that flecainide causes birth defects. Before taking flecainide, make sure your doctor knows if you are pregnant or if you may become pregnant.

Breast-feeding—Flecainide passes into breast milk. However, this medicine has not been shown to cause problems in nursing babies.

Children—Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of flecainide in children with use in other age groups.

Older adults—Elderly people are especially sensitive to the effects of flecainide. Flecainide may be more likely to cause irregular heartbeat in the elderly.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking flecainide it is especially important that your health care professional knows if you are taking any of the following:

• Other medicine for heart rhythm problems—Both wanted and unwanted effects on the heart may increase

• Congestive heart failure—Flecainide may make this condition worse

• Kidney disease or
• Liver disease—Effects of flecainide may be increased because of slower removal from the body

• Recent heart attack—Risk of irregular heartbeats may be increased

• If you have a pacemaker—Flecainide may interfere with the pacemaker and require more careful follow-up by the doctor

Take flecainide exactly as directed by your doctor, even though you may feel well. Do not take more medicine than ordered.

This medicine works best when there is a constant amount in the blood. To help keep this amount constant, do not miss any doses. Also, it is best to take the doses 12 hours apart, in the morning and at night , unless otherwise directed by your doctor. If you need help in planning the best times to take your medicine, check with your health care professional.

Dosing—

The dose of flecainide will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of flecainide. If your dose is different, do not change it unless your doctor tells you to do so.

The number of tablets that you take depends on the strength of the medicine.

• For oral dosage form (tablets):
  • For correcting irregular heartbeat:
    • Adults—50 to 150 milligrams (mg) every twelve hours.
    • Children—Use and dose must be determined by your doctor.

Missed dose—

If you miss a dose of flecainide and remember within 6 hours, take it as soon as possible. However, if you do not remember until later, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

It is important that your doctor check your progress at regular visits to make sure the medicine is working properly. This will allow for changes to be made in the amount of medicine you are taking, if necessary.

Your doctor may want you to carry a medical identification card or bracelet stating that you are using this medicine.

Before having any kind of surgery (including dental surgery) or emergency treatment, tell the medical doctor or dentist in charge that you are taking this medicine.

Flecainide may cause some people to become dizzy, lightheaded, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert.

If you have been using this medicine regularly for several weeks, do not suddenly stop using it. Check with your doctor for the best way to reduce gradually the amount you are taking before stopping completely.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• Less common
  • Chest pain;  irregular heartbeat;  shortness of breath;  swelling of feet or lower legs;  trembling or shaking 
  
  

• Rare
  • Yellow eyes or skin 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Blurred vision or seeing spots;  dizziness or lightheadedness 
  
  

• Less common
  • Anxiety or mental depression;  constipation ;  headache;  nausea or vomiting ;  skin rash;  stomach pain or loss of appetite;  unusual tiredness or weakness  
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.