Generic Name: propafenone, Oral tablet

Rythmol

All Brands

  • Rythmol
SECTION 1 of 4

Highlights for propafenone

Oral tablet
1

Propafenone is an oral drug that’s used to treat irregular heart rate in the conditions atrial fibrillation or flutter, ventricular arrhythmias, and paroxysmal supraventricular tachycardia. It helps prevent irregular heartbeats from happening again.

2

Your dose depends on the condition that’s being treated, the form of the drug you take, and how you respond to the medication. Your doctor will decide a dose that’s right for you.

3

Before you start propafenone, your doctor will do a test called an electrocardiogram to see how well your heart is working.

4

Common side effects include having a strange taste in your mouth, nausea, vomiting, dizziness, constipation, headache, tiredness, and rapid heart rate.

5

Avoid propafenone if you have uncontrolled heart failure, a slow heartbeat and other heart conditions, low blood pressure, or low potassium levels.

IMPORTANT INFORMATION

FDA Warning

This drug has a Black Box Warning. This is the most serious warning from the Food and Drug Administration (FDA). A black box warning alerts doctors and patients to potentially dangerous effects.

Warning: This drug should only be used to treat life-threatening abnormal heart rates. This drug, like many other medications that treat irregular heart rate, can increase your risk of death. Your risk may be higher if you have structural heart disease.

Other health conditions risk

Propafenone can make other health conditions worse. These include:

  • heart failure
  • cardiogenic shock. In this condition, your heart isn’t able to pump enough blood to the rest of your body.
  • heart conduction problems where your heart rate is too slow without a pacemaker. You may be able to use this drug if you have a pacemaker.
  • Brugada syndrome, a heart condition
  • very slow heart beat
  • very low blood pressure
  • lung disorders such as bronchitis or emphysema
  • abnormal levels of salts (electrolytes) in your body

Irregular heart rate warning

Propafenone can cause new or worsen irregular heart rate problems (proarrhythmic effects). This can be fatal. Your doctor will do an electrocardiogram test to check how well your heart is working before starting and during treatment with propafenone.

Low sperm count risk

Men who take propafenone may have a lower sperm count. This may make it harder for your partner to get pregnant.

Risk of Infection

In the beginning of treatment, propafenone can cause very low levels of white blood cells in your body. This may make it easier for you to catch an infection. The levels of these blood cells may return to normal after 14 days of treatment. Tell your doctor if you have signs of an infection, such as:

  • fever
  • sore throat
  • chills

Drug Features

Propafenone is a prescription drug. It’s available in these forms: oral tablets and oral extended-release capsules.

Propafenone is available in its generic form. Generic drugs usually cost less. In some cases they may not be available in every strength or form as the brand.  Talk to your healthcare provider to see if the generic will work for you.

Why It's Used

Propafenone is used to treat abnormal heart rate in the conditions atrial fibrillation or flutter, ventricular arrhythmias, and paroxysmal supraventricular tachycardia.

How It Works

Propafenone belongs to a class of drugs called antiarrhythmics. It’s a class 1c antiarrhythmic.

See Details

How It Works

Propafenone belongs to a class of drugs called antiarrhythmics. It’s a class 1c antiarrhythmic. A class of drugs refers to medications that work similarly. They have a similar chemical structure and are often used to treat similar conditions.

This drug works by making the heart stable. It works on the muscles of your heart to keep your heart rate normal.

SECTION 2 of 4

propafenone Side Effects

Oral tablet

Most Common Side Effects

The most common side effects that occur with propafenone include:

  • strange taste in your mouth

  • nausea

  • vomiting

  • dizziness

  • constipation

  • headache

  • tiredness

  • rapid or slow heart rate

If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious Side Effects

If you experience any of these serious side effects, call your doctor right away. If your symptoms are potentially life threatening, or if you think you’re experiencing a medical emergency, call 9-1-1:

  • irregular heart rate. It can cause new or worsen an existing irregular heart rate. Your doctor will check your heart rate before starting and during treatment with propafenone. Symptoms may include:

    • chest pain
    • shortness of breath
    • dizziness
    • fainting
    • palpitations
  • heart failure. Symptoms may include:

    • swelling of your arms or legs
    • trouble breathing
    • sudden weight gain
  • changes in the way your pacemaker or defibrillator works. Your doctor will check your devices before and during treatment to make sure it’s working well.

  • very low levels of white blood cells in your body, making it easier for you to get infections. Symptoms of an infection may include:

    • fever
    • sore throat
    • chills
  • worse symptoms of myasthenia gravis, a condition that causes weakness in the muscles of your body. Symptoms may include:

    • vision problems
    • weakness
    • difficulty speaking
    • shortness of breath
  • lower sperm count

Pharmacist's Advice
Healthline Pharmacist Editorial Team

Propafenone doesn’t cause drowsiness.

This drug decreases irregular heart rates.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.
SECTION 3 of 4

propafenone May Interact with Other Medications

Oral tablet

Propafenone can interact with other medications, herbs, or vitamins you might be taking. That’s why your doctor should manage all of your medications carefully. If you’re curious about how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Note: You can reduce your chances of drug interactions by having all of your prescriptions filled at the same pharmacy. That way, a pharmacist can check for possible drug interactions.

Food Interactions

Grapefruit or grapefruit juice can increase the amount of propafenone in your body. This can make your irregular heart rate worse. Don’t drink grapefruit juice or eat grapefruit while taking this drug.

Medications That Might Interact with This Drug

Digoxin

Propafenone can increase the level of digoxin in your body. Your doctor may need to adjust your dose of digoxin.

Heart and blood pressure drugs

Beta blockers, such as:

  • metoprolol (Lopressor, Toprol XL)
  • propranolol (Ineral LA)

Propafenone increases the levels of these drugs in your body. Your doctor may need to adjust your doses of these medications if you take them with propafenone.

Lidocaine

Lidocaine and propafenone can cause bad effects to your central nervous system when taken together. Don’t take these drugs together.

Blood thinner
  • warfarin 

Propafenone can increase levels of warfarin in your body. This can cause your blood to become thinner than normal. Your doctor may need to change your dose of warfarin.

Medicine to treat obesity
  • orlistat

This medicine can decrease the amount of propafenone in your body. This means that propafenone may not work as well. Avoid using orlistat together with propafenone.

Drug for tuberculosis
  • rifampin

This medicine can decrease the amount of propafenone in your body. This means that propafenone may not work as well.

Heart medicines
  • amiodarone
  • quinidine

These drugs can increase the amount of propafenone in your body. This can cause more side effects. These medicines shouldn’t be used with propafenone.

Medicine for upset stomach or stomach ulcers
  • cimetidine

This drug can increase the amount of propafenone in your body. This can cause more side effects. This medicine shouldn’t be used with propafenone.

Medicines for depression
  • desipramine

Don’t use desipramine with propafenone.

  • paroxetine
  • sertraline

These drugs can increase the levels of propafenone in your body causing an irregular heartbeat. You shouldn’t take these drugs with propafenone.

Medicines to treat infections
  • ritonavir
  • ketoconazole
  • saquinavir (taken with ritonavir)
  • erythromycin

These drugs can increase the levels of propafenone in your body causing an irregular heartbeat. You shouldn’t take these drugs with propafenone.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.

People with certain heartbeat disorders

Propafenone can worsen some heartbeat related problems such as slow heartbeat and others. Your doctor will check your heart rate before starting and during treatment with propafenone.

People with Brugada syndrome

Propafenone may reveal an underlying heart condition called Brugada syndrome. This is a type of arrhythmia that comes to light after you take propafenone.

People with heart failure

Propafenone works on the muscles of the heart, which can further worsen your heart failure. Don’t take this drug if you have heart failure.

People with a pacemaker

Propafenone can change the way your pacemaker works. Your doctor will check for these changes during your treatment and correct them.

People with liver problems

If your liver isn’t working well, propafenone levels can increase and build up in your body. This can lead to more side effects.

People with kidney problems

If your kidneys aren’t working well, the levels of this drug may increase in your body. This may cause more side effects.

People with myasthenia gravis

Propafenone can further worsen myasthenia gravis, a disorder that causes weakness in the muscles of your body. Tell your doctor if you notice any changes in your symptoms, such as weakness or vision problems.

Pregnant women

Propafenone is a category C pregnancy drug. That means two things:

  1. Research in animals has shown adverse effects to the fetus when the mother takes the drug.
  2. There haven’t been enough studies done in humans to be certain how the drug might affect the fetus.

Tell your doctor if you’re pregnant or plan to become pregnant. Propafenone should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Women who are nursing

Propafenone may pass through breast milk and cause serious effects in a breastfeeding child.

You and your doctor may need to decide if you’ll take propafenone or breastfeed.

For Seniors

Seniors may have decreased liver, kidney, and heart function. This means that it may take longer for this drug to clear from your body, which could lead to more side effects.

For Children

The effectiveness and safety of propafenone haven’t been established in people younger than 18 years old.

Allergies

Propafenone can cause a severe allergic reaction. Symptoms may include:

  • trouble breathing
  • swelling of your throat or tongue
  • hives

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal.

SECTION 4 of 4

How to Take propafenone (Dosage)

Oral tablet

All possible dosages and forms may not be included here. Your dose, form, and how often you take it will depend on: 

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

What Are You Taking This Medication For?

Episodic atrial fibrillation or flutter in people without structural heart disease
Form: Oral tablet
Strengths: 150 mg, 225 mg, and 300 mg
Form: Oral extended-release capsule
Strengths: 225 mg, 325 mg, and 425 mg
Adult Dosage (ages 18-64 years)

Immediate-release tablets:

  • Take 150 mg every 8 hours.
  • Your doctor may increase your dose after 3–4 days to 225–300 mg taken every 8 hours.

Extended-release capsules:

  • Take 225 mg every 12 hours.
  • Your doctor may increase your dose every 5 days up to 325 mg taken every 12 hours.
  • Your dose can be further increased to 425 mg taken every 12 hours.
Child Dosage (ages 0-17 years)

The safety and effectiveness of propafenone haven’t been established in people under 18 years old.

Senior Dosage (ages 65 years and older)

Your body may process this drug more slowly. Your doctor may start you on a lower dose so that too much of this drug doesn’t build up in your body. Too much of the drug in your body can be toxic. Your doses will be increased slowly.

Special Considerations

Kidney problems: Use this drug with caution.

Liver problems: The dose should be decreased by 20–30%.

Heart block or conduction disorders causing slow heartbeat: The dose should be decreased.

People with heart damage: Your starting dose of propafenone will be increased slowly.

Life-threatening ventricular arrhythmias in people without structural heart disease
Form: Oral tablet
Strengths: 150 mg, 225 mg, and 300 mg
Adult Dosage (ages 18-64 years)
  • Take 150 mg every 8 hours.
  • Your doctor may increase your dose after 3–4 days to 225–300 mg taken every 8 hours.
Child Dosage (ages 0-17 years)

The safety and effectiveness of propafenone haven’t been established in people under 18 years old.

Senior Dosage (ages 65 years and older)

Your body may process this drug more slowly. Your doctor may start you on a lower dose so that too much of this drug doesn’t build up in your body. Too much of the drug in your body can be toxic. Your doses will be increased slowly.

Special Considerations

Kidney problems: Use this drug with caution.

Liver problems: The dose should be decreased by 20–30%.

Heart block or conduction disorders causing slow heartbeat: The dose should be decreased.

People with heart damage: Your starting dose of propafenone will be increased slowly.

Paroxysmal supraventricular tachycardia
Form: Oral tablet
Strengths: 150 mg, 225 mg, and 300 mg
Adult Dosage (ages 18-64 years)
  • Take 150 mg every 8 hours.
  • Your doctor may increase your dose after 3–4 days to 225–300 mg taken every 8 hours.
Child Dosage (ages 0-17 years)

The safety and effectiveness of propafenone haven’t been established in people under 18 years old.

Senior Dosage (ages 65 years and older)

Your body may process this drug more slowly. Your doctor may start you on a lower dose so that too much of this drug doesn’t build up in your body. Too much of the drug in your body can be toxic. Your doses will be increased slowly.

Special Considerations

Kidney problems: Use this drug with caution.

Liver problems: The dose should be decreased by 20–30%.

Heart block or conduction disorders causing slow heartbeat: The dose should be decreased.

People with heart damage: Your starting dose of propafenone will be increased slowly.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always to speak with your doctor or pharmacist about dosages that are right for you.
Pharmacist's Advice
Healthline Pharmacist Editorial Team

Propafenone comes with serious risks if it’s not taken as prescribed.

If You Don’t Take it At All or If You Skip or Miss Doses

This drug is used to treat a chronic condition. There is no cure for these disorders, but taking propafenone will help you feel better. It’s important to continue taking your medication as directed by your doctor, even if you feel better. Doing so will give you the best chance of improving your quality of life.

If You Take Too Much

If you take too much, go to the emergency room right way. Symptoms may include low blood pressure, slow heartbeat, sedation, or arrhythmia.

What to Do If You Miss a Dose

If you miss a dose, skip the missed dose and take your next dose at its normally scheduled time.

Never try to catch up by taking two doses at once. This could result in toxic side effects.

How to Tell If the Drug Is Working

You may be able to tell if this drug is working if you have a decrease in your heart rate and if your symptoms of weakness, dizziness, tiredness, and lightheadedness get better.

Your doctor will do a test called an electrocardiogram to check how well your heart is working and if propafenone is helping you. Ask your doctor if this medication is working for you.

Propafenone is a long-term drug treatment

The immediate-release propafenone tablets may be cut or crushed

Don’t crush or cut the extended-release (ER) capsules or sustained-release (SR) capsules of this medication.

Store propafenone at room temperature

Keep it in temperatures from 59–86°F (15--30°C).

Keep this drug away from light and high temperature.

Keep your drugs away from areas where they could get wet, such as bathrooms. Store this drug away from moisture and damp locations.

Travel

When traveling with your medication:

  • Always carry your medication with you or in your carry-on bag.
  • Don’t worry about airport X-ray machines. They can’t hurt this medication.
  • You may need to show your pharmacy’s label to clearly identify the medication.
  • Keep the original prescription label with you when traveling.

Clinical Monitoring

Your doctor will monitor you before starting and during treatment with propafenone to make sure that the drug is safe for you to take. The following will be checked:

  • electrocardiogram, a test that checks your heart rate and rhythm 
  • kidney function
  • liver function
  • if your pacemaker is working properly
  • white blood cell count. This drug can decrease the level of white blood cells in your body. This makes you more likely to get an infection.
  • antinuclear antibodies test to make sure that your immune system isn’t attacking itself.

Insurance

Many insurance companies will require a prior authorization before they approve the prescription and pay for propafenone.

Are There Any Alternatives?

There are other drugs available to treat your condition. Some may be more suitable for you than others. Talk to your doctor about possible alternatives.

What does the pill look like?

Showing - out of 29

Content developed in collaboration with University of Illinois-Chicago, Drug Information Group

Medically reviewed by Creighton University, Center for Drug Information and Evidence-Based Practice on June 30, 2015

Send us your feedback

Thank you.

Your message has been sent.

We're sorry, an error occurred.

We are unable to collect your feedback at this time. However, your feedback is important to us. Please try again later.

Disclaimer: Healthline 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 other 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.

Read This Next

The Best Atrial Fibrillation Blogs of the Year
The Best Atrial Fibrillation Blogs of the Year
AFib Drugs: Prescriptions and Guidelines
AFib Drugs: Prescriptions and Guidelines
Living with Atrial Fibrillation
Living with Atrial Fibrillation
Advertisement
Advertisement
Advertisement