Flecainide oral tablet side effects: A detailed guide

This article describes possible side effects of flecainide oral tablet. You’ll also find information on cost savings and coupon options for flecainide. You can explore this overview article to learn more about flecainide oral tablet, including the drug’s uses, side effects, ways to save on cost, and more.

Flecainide oral tablet is a generic medication. It isn’t available in a brand-name version.

Boxed warnings

Flecainide has boxed warnings about the risk of death or nonfatal heart attack and new or worsened irregular heart rhythms. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

For details, see the “Side effects of flecainide in detail” section below.

More common side effects of flecainide

Flecainide oral tablet may cause mild or serious side effects. Below are some of the more common side effects of this medication.

Commonly reported side effects of flecainide oral tablet include:

• dizziness*
• changes in vision, such as blurry vision or spots in your vision
• shortness of breath
• headache
• nausea

* To learn more about this side effect, see the “Side effects of flecainide in detail” section below.

Mild side effects of flecainide

Flecainide may cause certain mild side effects. Usually, mild side effects are temporary and can be easily managed. Tell your doctor or pharmacist if you have side effects that don’t go away or become bothersome.

Mild side effects of flecainide oral tablet that occurred in studies include:

• dizziness*
• changes in vision, such as blurry vision or spots in your vision
• shortness of breath
• headache
• nausea
• fatigue (low energy)
• weakness
• heart palpitations (feeling of skipped or extra heartbeats)
• angina (chest pain)
• tremors (uncontrollable shaking in a part of your body)
• constipation
• abdominal pain
• edema (fluid buildup in your body)
• mild allergic reaction*†

Flecainide oral tablet may cause more mild side effects than those listed above. For details, see the drug’s prescribing information.

* To learn more about this side effect, see the “Side effects of flecainide in detail” section below.
† An allergic reaction is possible with flecainide oral tablet. But it’s unclear whether this side effect occurred in the drug’s studies.

Serious side effects of flecainide

Flecainide may cause certain serious side effects. If you have any serious side effects from flecainide oral tablet, call your doctor right away. But if you think you’re having a medical emergency or your side effects feel life threatening, take immediate action. Call 911 or a local emergency number, or go to the nearest emergency room.

After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Visit MedWatch’s website if you’d like to notify the FDA about a side effect you’ve had with flecainide.

Serious side effects of flecainide oral tablet that occurred in studies include:

• liver problems, such as liver failure
• heart problems, such as heart failure or heart block
• risk of death or nonfatal heart attack*
• risk of new or worsened irregular heart rhythms*
• severe allergic reaction†

* Flecainide oral tablet has a boxed warning for this side effect. A boxed warning is the most serious warning from the FDA. To learn more, see the “Side effects of flecainide in detail” section below.
† An allergic reaction is possible with flecainide oral tablet. But it’s unclear whether it occurred in the drug’s studies. To learn more about this side effect, see the “Side effects of flecainide in detail” section below.

Common questions about side effects of flecainide

Here are answers to some common questions about side effects of flecainide oral tablet. If you have other questions, talk with your doctor or pharmacist.

Are side effects of flecainide similar to those seen with metoprolol?

Flecainide and metoprolol are both prescribed for irregular heart rhythms, but they belong to different groups of drugs. They have some similar side effects. For example, both drugs can cause dizziness, fatigue (low energy), and slow heart rate.

But these drugs also have different side effects. For example, flecainide can cause new or worsening irregular heart rhythms. And, in rare cases, metoprolol can cause hallucinations.

To find out more about how these drugs compare, talk with your doctor.

Does flecainide cause long-term side effects?

No, long-term side effects aren’t expected with flecainide oral tablet. In studies, specific side effects weren’t seen in people who had taken the drug for a long time. Long lasting side effects after treatment ended also weren’t reported.

Talk with your doctor if you have questions about possible long-term side effects with flecainide.

Coupon for flecainide

Visit this page to access Optum Perks coupons and get price estimates for flecainide when you use the coupons. These coupons can provide significant savings on your prescription costs. 

Note: Optum Perks coupons cannot be used with insurance copays or benefits.

Side effects of flecainide in detail

Below you’ll find details on some of the side effects of flecainide oral tablet.

Risk of death or nonfatal heart attack

In studies, fatal or nonfatal heart attack were rare in people taking flecainide oral tablet. Certain factors can raise the risk of these side effects with flecainide oral tablet. These include having had a heart attack in the past two years and having an irregular heart rhythm that’s not life threatening.

With a heart attack, your heart doesn’t get enough oxygen to work correctly. This can be life threatening. Symptoms may include feeling pain, pressure, or tightness in your chest. This may spread to your jaw, neck, shoulder, or arm.

Ways to manage

If you experience symptoms of a heart attack, call 911 or your local emergency number right away, or go to your nearest emergency room.

If you’re concerned about the risks of heart attack or death with flecainide, talk with your doctor. They’ll likely only prescribe flecainide if your irregular heart rhythm is life threatening. Talk with your doctor about whether the benefits of taking flecainide for your condition outweigh its risks.

Risk of new or worsened irregular heart rhythms

In studies, new or worsened irregular heart rhythms were rare in people taking flecainide oral tablet. This side effect may be serious.

With irregular heart rhythms, the upper or lower chambers of your heart contract in an unusual rhythm or at an abnormal rate. Symptoms may include:

• feeling your heart is racing, pounding, skipping beats, or adding extra beats
• angina (chest pain)
• dizziness
• feeling lightheaded or faint

Certain factors can raise the risk of serious irregular heart rhythms with flecainide oral tablet. These include having atrial fibrillation (AFib) or atrial flutter.

Ways to manage

If you have concerns about new or worsened irregular heart rhythms, tell your doctor. They can discuss whether flecainide is right for you and if your treatment should be started in the hospital.

If you have chronic (long-term) AFib or atrial flutter, your doctor will likely not prescribe flecainide. Ask them about other treatments that may be better options for you.

Dizziness

Dizziness was common in studies of people taking flecainide oral tablet. This side effect is usually mild. Note that dizziness can also be a symptom of irregular heart rhythms, which flecainide is used to treat.

With dizziness, you may feel that you or your surroundings are spinning. You may also feel lightheaded or faint. Other symptoms may include nausea and sweating.

Certain factors can increase the risk of dizziness with flecainide oral tablet. These include low blood pressure and taking certain other medications. 

Ways to manage

If you experience dizziness, it may help to sit or lie down until the feeling passes. If the dizziness is severe, bothersome, or doesn’t go away, tell your doctor. They may need to adjust your dosage of flecainide or other medications you may take.

Allergic reaction

For some people, flecainide oral tablet can cause an allergic reaction. But it’s not clear whether this side effect occurred in the drug’s studies.

Symptoms can be mild or serious, and they may include:

• itchiness
• skin rash
• swelling under the skin, usually affecting eyelids, lips, hands, or feet
• swelling of the mouth, tongue, or throat, which can make it hard to breathe
• flushing (temporary warmth, redness, or deepening of skin color)

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to flecainide oral tablet, your doctor may recommend taking a different medication instead.

Warnings for flecainide

Below are some factors you may want to discuss with your doctor before taking flecainide oral tablet.

Boxed warnings

This drug has boxed warnings about the risk of death or nonfatal heart attack and new or worsened irregular heart rhythms. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

For details, see the “Side effects of flecainide in detail” section above.

Other warnings

It may not be safe for you to take flecainide oral tablet if you have specific health conditions. These are sometimes called drug-condition interactions. Other factors also may affect whether flecainide oral tablet is a safe treatment option for you.

Before taking flecainide oral tablet, tell your doctor about your health and medications you take. Things to consider include:

• the type of irregular heart rhythm you have
• other heart conditions, such as heart failure or sick sinus syndrome
• if you have a pacemaker (permanent or temporary)
• low or high potassium levels
• liver problems
• past allergic reaction to flecainide

Flecainide and pregnancy

It’s not known whether flecainide oral tablet should be taken during pregnancy. If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking this medication.

Flecainide and breastfeeding

In general, flecainide oral tablet is considered safe to take while breastfeeding. That said, check with your doctor about whether they feel it’s safe for you specifically if you choose to breastfeed your child.

Flecainide and alcohol

Flecainide oral tablet is not known to interact with alcohol. However, flecainide and alcohol can cause similar side effects. These include dizziness, blurry vision, nausea, headache, and liver problems. You may have a higher risk of these side effects if you drink alcohol with flecainide.

If you drink alcohol, talk with your doctor about whether it’s safe to consume it during your treatment with flecainide oral tablet.

What to ask your doctor

This article describes common and serious side effects of flecainide oral tablet. If your doctor prescribes this medication, they can discuss possible side effects with you. Let your doctor know if you have concerns or questions about treatment with this medication.

Here’s a list of some possible questions you may want to ask your doctor:

• How can I tell if flecainide is making my irregular heart rhythm worse?
• Do my health conditions or medications raise my risk of side effects with flecainide?
• How do flecainide’s side effects compare with those of other treatment options for my condition?

Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.