April 26, 2017
Recommended Topic Related To:

Rythmol SR

"The US Food and Drug Administration (FDA) has received multiple adverse event reports associated with the use of the Vascu-Guard Peripheral Vascular Patch (Baxter International Inc) during carotid endarterectomy (CEA).



Rythmol SR


(propafenone hydrochloride) Extended Release Capsules

Read this Patient Information Leaflet before you start taking RYTHMOL SR and each time you get a refill. There may be new information. This information does not take the place of talking with your doctor about your medical condition or your treatment.


RYTHMOL SR is a prescription medicine that is used:

  • in certain people who have a heart rhythm disorder called atrial fibrillation (AF)
  • to increase the amount of time between having symptoms of AF

It is not known if RYTHMOL SR is safe and effective in children.

Who should not take RYTHMOL SR?

Do not take RYTHMOL SR if you have:

Talk to your doctor before taking RYTHMOL SR if you think you have any of the conditions listed above.

What should I tell my doctor before taking RYTHMOL SR?

Before you take RYTHMOL SR, tell your doctor if you:

  • have liver or kidney problems
  • have breathing problems
  • have symptoms including diarrhea, sweating, vomiting, or loss of appetite or thirst that are severe. These symptoms may be a sign of abnormal electrolyte levels in your blood.
  • have myasthenia gravis
  • have lupus erythematosis
  • have been told you have or had an abnormal blood test called Antinuclear Antibody Test or ANA Test
  • are pregnant or plan to become pregnant. It is not known if RYTHMOL SR will harm your unborn baby.
  • are breastfeeding or plan to breastfeed. RYTHMOL SR can pass into your milk and may harm your baby. You and your doctor should decide if you will breastfeed or take RYTHMOL SR. You should not do both.
  • have any other medical conditions

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. RYTHMOL SR and certain other medicines can affect each other and cause serious side effects. RYTHMOL SR may affect the way other medicines work, and other medicines may affect how RYTHMOL SR works.

Especially tell your doctor if you take:

  • amiodarone or other medicines for your abnormal heart beats
  • an antidepressant medicine
  • a medicine to treat anxiety
  • ritonavir (for example, KALETRA®, NORVIR®) or saquinavir (for example, INVIRASE®)
  • an antibiotic medicine
  • ketoconazole (for example, NIZORAL®)
  • digoxin (LANOXIN®)
  • warfarin sodium (for example, COUMADIN®, JANTOVEN®)

Know the medicines you take. Keep a list of them to show your doctor and pharmacist when you get a new medicine.

How should I take RYTHMOL SR?

  • Take RYTHMOL SR exactly as prescribed. Your doctor will tell you how many capsules to take and how often to take them.
  • To help reduce the chance of certain side effects, your doctor may start you with a low dose of RYTHMOL SR, and then slowly increase the dose.
  • Do not open or crush the capsule.
  • You may take RYTHMOL SR with or without food.
  • You should not drink grapefruit juice during treatment with RYTHMOL SR.
  • If you miss a dose of RYTHMOL SR, take your next dose at the usual time. Do not take 2 doses at the same time.
  • If you take too much RYTHMOL SR, call your doctor or go to the nearest hospital emergency room right away.
  • Call your doctor if your heart problems get worse.

What are possible side effects of RYTHMOL SR?

RYTHMOL SR can cause serious side effects including:

  • New or worsened abnormal heart beats, that can cause sudden death or be life-threatening. Your doctor may do an electrocardiogram (ECG or EKG) before and during treatment to check your heart for these problems.
  • New or worsened heart failure. Tell your doctor about any changes in your heart symptoms, including:
    • any new or increased swelling in your arms or legs
    • trouble breathing
    • sudden weight gain
  • Effects on pacemaker function. RYTHMOL SR may affect how an implanted pacemaker or defibrillator works. Your doctor should check how your pacemaker or defibrillator is working during and after treatment with RYTHMOL SR. They may need to be re-prog rammed.
  • Very low white blood cell levels in your blood (agranulocytosis). Your bone marrow may not produce enough of a certain type of white blood cells called neutrophils. If this happens, you are more likely to get infections. Tell your doctor right away if you have any of these symptoms, especially during the first 3 months of treatment:
  • Worsening of myasthenia gravis in people who already have this condition. Tell your doctor about any change in your symptoms.
  • RYTHMOL SR may cause lower sperm counts in men. This could affect the ability to father a child. Talk to your doctor if this is a concern for you.

Common side effects of RYTHMOL SR include:

Tell your doctor if you have any side effect that bothers you or that does not go away.

These are not all the possible side effects of RYTHMOL SR. For more information, ask your doctor or pharmacist.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

How should I store RYTHMOL SR?

  • Store RYTHMOL SR at room temperature between 59°F to 86°F (15°C to 30°C).
  • Keep the bottle tightly closed.

Keep RYTHMOL SR and all medicines out of the reach of children.

General information about RYTHMOL SR

Medicines are sometimes prescribed for conditions other than those described in patient information leaflets. Do not use RYTHMOL SR for a condition for which it was not prescribed by your doctor. Do not give RYTHMOL SR to other people, even if they have the same symptoms you have. It may harm them.

This leaflet summarizes the most important information about RYTHMOL SR. If you would like more information, talk with your doctor. You can ask your doctor or pharmacist for information about RYTHMOL SR that is written for healthcare professionals. For more information about RYTHMOL SR, call 1-888-825-5249.

What are the ingredients in RYTHMOL SR?

Active Ingredient: Propafenone hydrochloride

Inactive Ingredients: Antifoam, gelatin, hypromellose, red iron oxide, magnesium stearate, shellac, sodium lauryl sulfate, sodium dodecyl sulfate, soy lecithin and titanium dioxide.

Last reviewed on RxList: 6/1/2011
This monograph has been modified to include the generic and brand name in many instances.

Rythmol SR - User Reviews

Rythmol SR User Reviews

Now you can gain knowledge and insight about a drug treatment with Patient Discussions.

Here is a collection of user reviews for the medication Rythmol SR sorted by most helpful. Patient Discussions FAQs

Report Problems to the Food and Drug Administration


You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Heart Health

Get the latest treatment options.

Atrial Fibrillation Quiz