Rythmol SR

Generic Name: propafenone (proe PAF e none)

Brand Names: Rythmol, Rythmol SR

What is Rythmol SR (propafenone)?

Propafenone is in a group of drugs called Class IC anti-arrhythmics. It affects the way your heart beats.

Propafenone is used in certain situations to prevent serious heart rhythm disorders.

Propafenone may also be used for purposes not listed in this medication guide.

What is the most important information I should know about Rythmol SR (propafenone)?

You should not use this medication if you are allergic to propafenone, or if you have untreated or uncontrolled congestive heart failure, a heart condition called "sick sinus syndrome" or "AV block" (unless you have a pacemaker), slow heartbeats or severely low blood pressure, an electrolyte imbalance, or a breathing disorder such as asthma.

Before you take propafenone, tell your doctor if you have congestive heart failure, liver or kidney disease, lupus, arthritis, myasthenia gravis, or if you have had a heart attack within the past 2 years.

Call your doctor at once if you have a serious side effect such as weak pulse, slow breathing, feeling like you might pass out, feeling short of breath, swelling, rapid weight gain, pale skin, easy bruising or bleeding, unusual weakness, confusion, unusual thoughts or behavior, or seizure.

What should I discuss with my healthcare provider before taking Rythmol SR (propafenone)?

You should not use this medication if you are allergic to propafenone, or if you have:

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  untreated or uncontrolled congestive heart failure;

  
  


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  a heart condition called "sick sinus syndrome" or "AV block" (unless you have a pacemaker);

  
  


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  slow heartbeats or severely low blood pressure;

  
  


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  a severe or uncontrolled electrolyte imbalance (such as low levels of potassium in your blood); or

  
  


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  a breathing disorder such as severe COPD (chronic obstructive pulmonary disorder).

  
  

To make sure you can safely take propafenone, tell your doctor if you have any of these other conditions:

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  congestive heart failure;

  
  


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  a breathing disorder;

  
  


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  liver disease;

  
  


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  kidney disease;

  
  


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  lupus;

  
  


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  arthritis;

  
  


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  myasthenia gravis; or

  
  


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  if you have had a heart attack within the past 2 years.

  
  

FDA pregnancy category C. It is not known whether propafenone will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication. It is not known whether propafenone passes into breast milk or if it could harm a nursing baby. You should not breast-feed while you are using propafenone.

How should I take Rythmol SR (propafenone)?

Take exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results.

You may take propafenone with or without food.

Conditions that may cause very low blood pressure include: vomiting, diarrhea, heavy sweating, heart disease, dialysis, a low salt diet, or taking diuretics (water pills). Tell your doctor if you have a prolonged illness that causes diarrhea or vomiting.

To be sure this medication is helping your condition, your blood may need to be tested often. Visit your doctor regularly.

Store at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include extreme drowsiness, slow heart rate, feeling like you might pass out, or seizure (convulsions).

What should I avoid while taking Rythmol SR (propafenone)?

Grapefruit and grapefruit juice may interact with propafenone and lead to potentially dangerous effects. Discuss the use of grapefruit products with your doctor.

Rythmol SR (propafenone) side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Call your doctor at once if you have a serious side effect such as:

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  feeling short of breath, even with mild exertion;

  
  


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  swelling, rapid weight gain;

  
  


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  chest pain, rapid heart rate, pounding heartbeats or fluttering in your chest;

  
  


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  fever, chills, sore throat, flu symptoms, weakness;

  
  


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  confusion, unusual thoughts or behavior;

  
  


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  seizure; or

  
  


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  slow heart rate, weak pulse, fainting, slow breathing (breathing may stop).

  
  

Less serious side effects may include:

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  dizziness, anxiety, loss of balance or coordination;

  
  


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  unusual or unpleasant taste in your mouth;

  
  


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  nausea, vomiting, constipation, loss of appetite;

  
  


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  warmth, redness, or tingly feeling under your skin;

  
  


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  headache;

  
  


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  tired feeling;

  
  


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  ringing in your ears;

  
  


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  unusual dreams; or

  
  


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  blurred vision.

  
  

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Rythmol SR (propafenone)?

Many drugs can interact with propafenone. Below is just a partial list. Tell your doctor if you are using:

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  cimetidine (Tagamet),

  
  


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  digoxin (digitalis, Lanoxin);

  
  


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  ketoconazole (Nizoral);

  
  


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  orlistat (alli, Xenical);

  
  


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  quinidine (Quin-G);

  
  


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  rifampin (Rifadin, Rifamate, Rimactane);

  
  


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  a blood thinner such as warfarin (Coumadin, Jantoven);

  
  


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  an antidepressant such as desipramine (Norpramin), fluoxetine (Prozac), imipramine (Tofranil), paroxetine (Paxil), sertraline (Zoloft), or venlafaxine (Effexor);

  
  


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  HIV or AIDS medication such as ritonavir (Norvir, Kaletra) or saquinavir (Invirase);

  
  


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  another heart rhythm medication such as amiodarone (Cordarone, Pacerone);

  
  


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  medicine to treat psychiatric disorders, such as haloperidol (Haldol); or

  
  


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  a beta-blocker such as atenolol (Tenormin, Tenoretic), carvedilol (Coreg), labetalol (Normodyne, Trandate), metoprolol (Dutoprol, Lopressor, Toprol), nadolol (Corgard), propranolol (Inderal, InnoPran), sotalol (Betapace), and others.

  
  

This list is not complete and other drugs may interact with propafenone. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

More Rythmol SR resources

• Rythmol SR Side Effects (in more detail)
• Rythmol SR Use in Pregnancy & Breastfeeding
• Drug Images
• Rythmol SR Drug Interactions
• Rythmol SR Support Group
• 13 Reviews for Rythmol SR - Add your own review/rating

• Rythmol SR Prescribing Information (FDA)


• Rythmol SR Advanced Consumer (Micromedex) - Includes Dosage Information


• Rythmol SR Sustained-Release Capsules MedFacts Consumer Leaflet (Wolters Kluwer)


• Propafenone Prescribing Information (FDA)


• Propafenone MedFacts Consumer Leaflet (Wolters Kluwer)


• Propafenone Professional Patient Advice (Wolters Kluwer)


• Propafenone Hydrochloride Monograph (AHFS DI)


• Rythmol Prescribing Information (FDA)

Compare Rythmol SR with other medications

• Atrial Fibrillation
• Atrial Flutter
• Ventricular Tachycardia
• Wolff-Parkinson-White Syndrome

Where can I get more information?

• Your pharmacist can provide more information about propafenone.

See also: Rythmol SR side effects (in more detail)