- What is flecainide?
- How does flecainide work?
- Foods to avoid with flecainide
- Foods to eat while taking flecainide
- Other things to avoid while taking flecainide
- Should flecainide be taken with food?
- What is the best time to take flecainide?
- Side effects of flecainide
- Any other safety concerns?
- How to reduce the side effects of flecainide
- Natural flecainide alternatives
- Conclusion
Your heart is designed to maintain a steady, consistent heartbeat through its electrical system.
Issues with your heart’s electrical signaling can result in arrhythmias, which is when your heart doesn’t beat rhythmically.
Certain heart rhythm problems can increase your risk of serious complications like blood clots, stroke, and heart failure without treatment.
Many types of medications are designed to help support normal heart rhythm and reduce the severity and frequency of arrhythmias.
One of these antiarrhythmic drugs is flecainide.
We discuss what flecainide is, how it works, and possibly dietary changes you should make, including foods to eat and avoid when taking this medication.
What is flecainide?
Flecainide is a class of medications called antiarrhythmics. Antiarrhythmics like flecainide work to slow the electrical signals in your heart to stabilize your heart rhythm.
The FDA approved Flecainide in 1984. It received a Black Box warning from the FDA after a study published in 1991 showed that it might increase your risk of having a heart attack (myocardial infarction) or dying if you’d suffered a recent heart attack.
Flecainide isn’t commonly used except for cases of extreme and life-threatening heart rhythm abnormalities.
The reason flecainide isn’t commonly used is that people taking it (who had also had a heart attack within the last two years) were more likely to have another heart attack or die compared to those not taking flecainide, according to the 1991 study.
A 2011 paper noted that flecainide could be safe in many instances, but many health practitioners are deterred from using it based on the warnings from the 1991 study.
The common dosage of flecainide ranges between 50-150 milligrams twice a day (12 hours apart), depending on the condition it’s treating. Flecainide isn’t recommended if you have coronary artery disease or heart structure problems.
How does flecainide work?
Your heart beats when electrical signals tell the heart muscles to contract and relax in a certain order. Your heart rhythm should follow a standard pattern to be considered “normal” and healthy, which can be viewed with an electrocardiogram (ECG).
However, issues with this electrical signaling can cause your heart to beat out of rhythm, which can increase your risk of serious heart conditions like a heart attack or abnormal blood clotting.
If you have a heart arrhythmia, your healthcare provider or cardiologist (heart specialist) can view your ECG to determine what kind of arrhythmia you have. Some heart arrhythmias are benign (they don’t cause harm), while others are more dangerous.
Flecainide works to slow the nerve signals within your heart muscle, which can help normalize an abnormal heart rhythm, also called an arrhythmia. It does this by blocking sodium channels, which play a role in the electrical conduction in your heart.
Flecainide can be used to treat abnormal heart rhythms like paroxysmal supraventricular tachycardia, paroxysmal atrial fibrillation/flutter (PAF), and sustained ventricular tachycardia.
Based on up-to-date information at the time of this article, flecainide isn’t meant to treat chronic atrial fibrillation due to an abnormal heart structure because it could cause further heart rhythm abnormalities.

Foods to avoid with flecainide
There aren’t any specific foods that will interact with flecainide. However, if you’re taking flecainide, it’s because you have an abnormal heart rhythm. Therefore, a heart-healthy diet is recommended to promote your overall heart health.
Foods high in saturated fat
Some studies have found an association between diets high in saturated fat and an increased risk of heart attack or stroke. Newer studies stress that it doesn’t just come down to saturated fat in terms of heart disease risk, but your overall diet.
The bottom line is that it’s likely safe to eat saturated fat in moderation, but there may be heart health risks associated with consistently eating a diet very high in saturated fat.
Saturated fat is typically found in animal foods like high-fat meat and whole-fat dairy products, but are also found in some plant foods such as coconut and palm fruit.
It’s recommended to keep your total saturated fat intake to less than 10% of your total calories (less than 22 grams for a 2,000-calorie diet).
You may need to be even more mindful of your saturated fat intake if you have a history of heart disease, high cholesterol, or other risk factors for heart disease.
Here is a list of foods high in saturated fat to potentially limit or avoid while taking flecainide:
- beef (especially non-lean cuts)
- lamb
- pork
- poultry with the skin on
- lard and cream
- butter
- cheese
- ice cream
- coconut (including coconut oil)
- palm oil and palm kernel oil
- some baked and fried foods
Foods high in sodium
Sodium, one of the compounds in table salt, can exacerbate heart problems if you regularly consume it in large amounts. Excessive sodium intake causes your body to retain fluid, which can increase your blood pressure. Over time, high blood pressure can weaken areas of your heart and increase your risk of heart disease.
High blood pressure might also worsen or trigger heart rhythm problems, which is the primary condition flecainide is meant to treat.
Many of the highest-sodium foods are processed foods and convenience foods. Some examples of high-sodium foods to limit or avoid while taking flecainide are:
- Deli and cured meats
- Salty snacks (chips, pretzels, etc.)
- Quick-bread mixes
- Canned soups
- Frozen entrees
- Fast food like pizza, salted French fries, etc.
High amounts of caffeine
Caffeine is a stimulant that can exacerbate heart arrhythmias. Low- to moderate amounts of caffeine might be tolerated while taking flecainide, but it’s probably a good idea to avoid excessive amounts of caffeine.
Aim to be mindful of your intake of things like:
- Coffee drinks, especially espresso beverages
- Energy drinks or shots
- Foods or drinks with added caffeine, such as some codas
- Chocolate containing a high percentage of cacao
- Black tea
Alcohol
Drinking alcohol is associated with an increased risk of heart rhythm abnormalities such as atrial fibrillation, as well as other heart problems. Drinking excessive amounts of alcohol might also worsen existing arrhythmias.
Aim to keep your alcohol intake within the recommended limit of one or fewer drinks per day for women and two or fewer drinks per day for men.
Foods to eat while taking flecainide
Now you know what foods to avoid when taking flecainide, what should you eat?
A primarily plant-based eating plan such as a Mediterranean diet can help support your heart health. A Mediterranean diet is lower in sodium, saturated fat, and added sugar compared to a typical Western diet.
Nuts and seeds
Nuts and seeds are a good source of magnesium, a mineral that plays a role in supporting normal heart rhythm. Magnesium deficiencies can increase your risk of certain heart arrhythmias and can effectively treat ventricular and supraventricular arrhythmias.
Nuts and seeds are also sources of healthy unsaturated fats as well as omega-3 fatty acids. Opt for nuts and seeds such as:
- Walnuts
- Almonds
- Chia seeds
- Flax seeds
- Pistachios
- Pumpkin seeds
Whole grains
Compared to refined grains, whole grains are richer in nutrients and fiber. Fiber-rich diets can help reduce your risk of heart disease by promoting healthy cholesterol levels. If you suffer from constipation while taking flecainide, fiber-rich foods can help promote regular bowel movements.
Some examples of whole grains to include while taking flecainide include:
- Whole wheat bread or grains made with whole wheat flour
- Brown rice
- Barley
- Whole oats
- Bulgur
Lean protein
Lean protein sources are lower in saturated fat, which might help promote heart health. Some lean protein sources to consider include:
- Poultry (skinless)
- Lean beef
- Fish
- Eggs
- Beans & lentils (also a good source of fiber and potassium)
- Soybeans (tofu, edamame, etc.)
Fruits and vegetables
Fruits and vegetables are rich in potassium and antioxidants that can help support healthy blood pressure levels and heart health. Aim to include a variety of colors of produce to benefit from the different types of phytochemicals, which help fight inflammation and promote heart health.
- Dark leafy green vegetables
- Berries (blueberries, raspberries, blackberries, and strawberries)
- Citrus fruits
- Orange vegetables like carrots and pumpkin
- Eggplant

Other things to avoid while taking flecainide
Certain medications
You should speak to your healthcare provider if you’re taking any of the following medications, which might affect the way flecainide works.
- Digoxin (a medication used to treat heart failure)
- Any diuretic or “water pill”
- Beta-blockers like atenolol, metoprolol, propranolol, and sotalol
- Other heart medications such as amiodarone, diltiazem, disopyramide, nifedipine, quinidine, or verapamil
- Anti-seizure medications
Smoking
Smoking tobacco increases your risk of heart disease and can cause high blood pressure. Cigarette smoking may also be responsible for causing heart arrhythmias and increasing your risk of coronary artery disease and chronic obstructive pulmonary disease (COPD).
Other smokeless tobacco products like chewing tobacco can still increase your blood pressure and heart rate, which will likely worsen heart arrhythmias.
Should flecainide be taken with food?
Flecainide can be taken with or without food. You should take your flecainide doses 12 hours apart, so be sure to keep consistent with your dosing regimen.
What is the best time to take flecainide?
You can take flecainide at any time, but it’s important to keep the amount consistent in your bloodstream. Doses of flecainide are meant to be taken 12 hours apart, so you should choose times when you can consistently follow through with the dosing schedule.
For instance, if you are usually in bed by 9 PM, you should aim to take your first flecainide dose no later than 9 AM so you can take your second dose before bedtime.
Side effects of flecainide
Some of the more common side effects of flecainide include:
- dizziness
- changes in vision
- headache
- weakness
- uncontrollable shaking of a part of your body
- constipation
- stomach pain
If you experience any of these more alarming side symptoms while taking flecainide, be sure to seek prompt medical attention:
- fast, pounding, or irregular heartbeat
- chest pain
- shortness of breath
- extreme tiredness
- nausea
- loss of appetite
- persistent cough with blood-tinged mucus
- swelling of your hands, feet, ankles, or lower legs
- confusion
- unusual bleeding or bruising
- pain in the upper right part of your stomach
- yellowing of your skin or eyes
- flu-like symptoms

Any other safety concerns?
Because flecainide can make you feel lightheaded and dizzy, you should avoid potentially dangerous situations like climbing ladders or operating machinery until you get used to how flecainide makes you feel.
How to reduce the side effects of flecainide
Flecainide comes with side effects that often can’t be avoided because it’s impacting your heart’s rhythm. You can reduce the risk of severe side effects by taking flecainide as prescribed and not taking doses closer than 12 hours apart.
Natural flecainide alternatives
Magnesium supplementation
Some healthcare providers suggest magnesium supplementation in patients experiencing heart arrhythmias. Certain types of arrhythmias respond very well to magnesium supplementation.
If you don’t consistently eat a diet rich in magnesium, a magnesium supplement providing 300 milligrams may be beneficial.
Coenzyme Q10
Coenzyme Q10 is an antioxidant that your body produces on its own. Studies show that coenzyme Q10 (CoQ10) may help reduce the severity of heart arrhythmias such as afib.
Vitamin C
Vitamin C is an antioxidant that might play a role in your heart health. This vitamin has been studied for its ability to prevent atrial fibrillation among post-cardiac surgery patients at higher risk of atrial fibrillation.
You can easily find vitamin C supplements, but can also obtain vitamin C from plant foods such as:
- Citrus fruits (oranges, kiwis, lemons, grapefruit)
- Bell peppers
- Strawberries
- Tomatoes
- Cruciferous vegetables like broccoli, Brussels sprouts, cabbage, and cauliflower
- White potatoes
Conclusion
Flecainide is an antiarrhythmic drug meant to help treat certain times of heart arrhythmias.
The safety of flecainide has been questioned based on a study suggesting that flecainide might increase your risk of heart attack or death if you’ve recently experienced a heart attack.
To support your heart health and help reduce the severity of heart arrhythmias while taking flecainide, a heart-healthy diet with plenty of plant-based foods is recommended.
Aim to include lean proteins, healthy fats, fruits, vegetables, and whole grains in your diet while taking flecainide.
Avoid foods high in saturated fat and sodium while taking flecainide. In addition to avoiding these foods, you should also limit or avoid alcohol, abstain from smoking, and avoid heavy caffeine intake when taking flecainide.
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