What to Expect When Starting Propafenone

Stethoscope next to a heart.
  • Propafenone is a type of antiarrhythmic medication prescribed for the treatment of cardiac conditions that cause irregular heartbeats.

  • It works by stabilizing the electrical activity in the heart, which allows the muscle to maintain a more regular rhythm.

  • This medication can cause mild to moderate side effects. Mild effects typically resolve on their own, but more serious adverse reactions — like new or worsening irregular heartbeats — may require professional medical attention.

  • Propafenone may not be suitable for certain groups of people, including pregnant and breastfeeding women, people with specific health conditions, and seniors. Your doctor will help you determine if this is the most appropriate treatment for your condition.

Arrhythmia — a condition characterized by abnormal heart rhythm — is a health complication that affects around 5% of Americans in their lifetimes.

These conditions can cause difficulties in your everyday life, which is why proper treatment is crucial.

Medications like propafenone are well-known for their ability to help individuals manage common arrhythmias.

In this article, we’ll take a closer look at how propafenone is used, the potential side effects it can cause, and which special precautions you should take while using this medication.

Understanding how this drug works can help you know what to expect and how to identify serious side effects that require medical attention.

What is Propafenone and What is it Used for?

Propafenone is a type of antiarrhythmic medication primarily used to treat certain types of irregular heartbeats — especially those that develop in the atria (upper chambers of the heart).

This medication is often prescribed to individuals with atrial fibrillation or atrial flutter and certain types of supraventricular tachycardias.

It works by stabilizing the electrical activity of the heart, helping the muscle to maintain a steady and regular beat.

What is the Dosage for Propafenone and How is it Administered?

Propafenone is available as a tablet or extended-release capsule taken orally with water.

Your doctor may recommend a lower dosage and adjust it over time. Propafenone is available as a 150 mg, 225 mg, and 300 mg tablet.

Due to the side effects associated with propafenone, doctors typically prescribe the lowest possible dosage that will be effective in treating your condition.

Depending on the severity of your condition and your doctor’s specific instructions, adults usually take propafenone every 8 to 12 hours.

Senior patients using propafenone will receive a tailored treatment regimen to avoid the accumulation of the drug in their system due to slow metabolization.

The safety and effectiveness of this medication in people younger than 18 have not been established yet.

Key Point: Propafenone Boxed Warning

Propafenone contains a boxed warning, which is the most serious alert that the Food and Drug Administration (FDA) can apply to medication.

This drug’s warning notifies doctors that propafenone should only be used to treat life-threatening and abnormal heart conditions.

This medication — like many others that treat irregular heart rhythms — can increase the risk of fatalities, and people suffering from structural heart disease may be more at risk.

Which Side Effects Does Propafenone Cause?

Propafenone can cause mild to serious side effects that may require medical attention.

Mild side effects are more common and tend to resolve within a few days or weeks as the body adjusts to the medication. These may include:

  • Nausea
  • Vomiting
  • Dizziness
  • Headaches
  • Tiredness
  • Constipation
  • Slow heart rate
  • A strange or metallic taste in the mouth

The following are also mild side effects, but they are less common:

  • Chest pain
  • Fast heart rate
  • Lightheadedness
  • Weight gain

If any of these side effects don’t improve or worsen within a couple of weeks, speak to your doctor as soon as possible.

When are propafenone side effects serious?

Being able to recognize the serious side effects of propafenone may save your life in an emergency.

If any of the following side effects occur, call your doctor immediately or seek emergency medical care:

  • New or worsening irregular heart rate that is accompanied by symptoms of chest pain, shortness of breath, dizziness, fainting, and palpitations.

  • Heart failure which may include symptoms like swelling of the arms or legs (peripheral edema), trouble breathing, and sudden weight gain.

  • Low white blood cell count that typically manifests as a fever, sore throat, and chills. Men may also have a decreased sperm count.

These side effects could be fatal if left untreated, so it’s important to get proper care as soon as you can.

Does Propafenone Interact with Any Other Medications?

Propafenone can interact with a number of medications that may have different reactions. Some may interfere with its effectiveness, while other drugs can increase the side effects of propafenone.

The following medications have known drug interactions with propafenone:

  • Digoxin: Propafenone can increase the amount of digoxin in the body, causing complications in managing cardiac conditions. Digoxin is a medication commonly used to treat heart failure and certain types of arrhythmias.

  • Metoprolol and propranolol: These beta-blockers can be affected by propafenone and may disrupt their effectiveness.

  • Lidocaine: Using propafenone alongside lidocaine can cause irreversible damage to your central nervous system. These drugs should not be taken together under any circumstances.

  • Warfarin: Taking blood thinners with propafenone can cause you to bleed more easily or spontaneously, which could be dangerous.

  • Medication to treat obesity: Medications like orlistat can decrease the amount of propafenone in the body, which can reduce its effectiveness. It’s not recommended to use these drugs together.

  • Rifampin: Drugs used to treat tuberculosis should not be taken with propafenone as they can decrease its effectiveness.

  • Medications used to treat infections: Certain drugs that treat bacterial or viral infections can increase propafenone levels in the body. This can cause an irregular heartbeat which may lead to additional complications.

  • Antidepressants: These medications can increase the levels of propafenone in the body, which may cause further cardiac complications.

  • Cimetidine: This medication is used to manage an upset stomach or ulcers and can increase propafenone levels, causing more side effects.

Certain heart medications: Some drugs used to treat heart conditions can increase the levels of propafenone in the body and may affect heart functioning. This can cause serious side effects and make you more vulnerable to experiencing a life-threatening cardiac event.

Older man wearing a checkered shirt smiling at the camera.

Warnings, Considerations, and Precautions

Special dosage considerations

Propafenone should be administered with caution in the following groups of people:

  • Individuals with liver problems
  • People with heart block or conduction disorders
  • Those with heart damage or previous heart failure
  • Individuals who suffer from cardiogenic shock
  • People with Brugada syndrome
  • Those with abnormal electrolyte levels
  • Individuals with lung disorders
  • Those with very low blood pressure (hypotension)

Using propafenone while suffering from these conditions can make your symptoms worse and negatively affect your quality of life.

If this medication is absolutely necessary to treat an irregular heartbeat, your doctor will usually prescribe it at a much lower dosage than normal. Usage warnings

Propafenone might not be suitable for certain groups of people, and your doctor may recommend an alternative treatment method if you fall into these categories:

  • Pregnant women: No human trials have been conducted to establish if propafenone can be harmful to your unborn baby. If you are currently expecting or planning to become pregnant, tell your doctor to avoid potential complications.

  • Women who are breastfeeding: There is a risk that propafenone may pass through breast milk and negatively affect your baby. It’s recommended to discuss these risks with your doctor before you start taking propafenone.

  • Seniors: Elderly people may have decreased liver, kidney, and heart function. This means that it can take longer for propafenone to clear from the body, which could worsen side effects.

Follow the dosage instructions

Propafenone is intended to be used as a long-term treatment, so it’s important to follow the usage guidelines recommended by your doctor.

Not only is this essential for ensuring your condition is treated correctly, but it can also help you avoid unpleasant side effects.

If you skip a dose, you might put yourself at risk of worsening your condition and developing further complications.

However, do not double up on your medication if you have a missed dose. This can cause a potentially fatal overdose.

It’s recommended to skip the dose you miss and take the next one at its scheduled time.

Key Point: Can You Overdose on Propafenone?

If you take two or more doses of propafenone at the same time, you may overdose on this medication. An overdose can be life-threatening and may include the following symptoms:

  • Low blood pressure
  • Slow heartbeat
  • Sleepiness
  • Irregular heartbeat

An overdose requires emergency medical attention, and you should call 911 right away. You can also contact your local Poison Control Center for help.

Are There Any Alternatives to Propafenone?

There are various alternative options for treating irregular heartbeats, particularly for individuals with liver disease who may not be able to take propafenone. Popular options include:

  • Amiodarone: This is an antiarrhythmic medication that can be used to treat various types of irregular heart conditions. It has a different mechanism of action compared to propafenone and is generally a safer option for individuals with liver disease.

  • Sotalol: Sotalol is a beta-blocker that also has antiarrhythmic properties. It’s used to treat arrhythmias and may be considered an alternative for individuals who can’t use propafenone.

  • Dronedarone: Dronedarone is a medication that is used to treat atrial fibrillation. It has a similar mechanism of action to amiodarone but with fewer side effects, making it a suitable alternative to propafenone.

It is important to consult your healthcare professional to determine the most appropriate alternative treatment option based on your overall well-being.

Your doctor can assess your situation and recommend the most suitable treatment plan to manage your condition effectively.

When Should You See a Doctor About Taking Propafenone?

Propafenone is only available by prescription, so you’ll need to see your doctor to obtain this medication.

This also allows your healthcare provider to assess your condition and determine if propafenone is the right treatment option for you.

During the consultation, you should tell your doctor about any existing medical conditions or allergies you have and which medications you’re currently taking.

Propafenone can interact with a number of drugs and conditions, making it unsuitable for certain people. Disclosing your medical history to your physician is essential to ensure safe and effective treatment.

If you’ve already started using propafenone, you should see your doctor if you develop any unusual, worsening, or persistent side effects.

Adverse reactions that don’t improve with time may cause further complications and could also indicate that propafenone isn’t the right treatment option for your condition.

It’s also important to schedule regular follow-up checks with your doctor once you start using this medication. This allows them to monitor your symptoms and adjust your dosage if necessary.

Where Can You Learn More About Propafenone and Similar Drugs?

If you’re concerned about your heart condition or want to know more about medications like propafenone, LifeMD can help.

A team of licensed medical professionals can provide you with information and guidance on how to keep your heart healthy and use propafenone safely — all from the comfort of your home.

Make an appointment today to learn more about how LifeMD can help you manage your heart health.

LifeMD makes it easy to stay on top of your health because talking to a doctor, filling your prescriptions, getting your labs done—and more—are all easy and cost-effective.
Come discover a healthcare solution built around you and your life.

Connect with a doctor now!

This article is intended for informational purposes only and should not be considered medical advice. Consult a healthcare professional or call a doctor in the case of a medical emergency.

Learn Why Over 600,000 People Have Trusted LifeMD

Become a member today and start experiencing why our patients love our level of medical care, service, and accessibility.