Propafenone

This information from Lexicomp^® explains what you need to know about this medication, including what it’s used for, how to take it, its side effects, and when to call your healthcare provider.

Brand Names: US

Rythmol SR [DSC]

Brand Names: Canada

APO-Propafenone; MYLAN-Propafenone; PMS-Propafenone [DSC]; Rythmol

What is this drug used for?

• It is used to treat certain types of abnormal heartbeats.

What do I need to tell my doctor BEFORE I take this drug?

• If you are allergic to this drug; any part of this drug; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
• If you have any of these health problems: Breathing or lung problems, Brugada syndrome, electrolyte problems in your blood, low blood pressure, recent heart attack, sick sinus syndrome or heart block without a working pacemaker, shock caused by heart problems, slow heartbeat, or heart failure.
• If you have been taking any drugs to treat a heartbeat that is not normal.
• If you take any drugs (prescription or OTC, natural products, vitamins) that must not be taken with this drug, like certain drugs that are used for HIV, infections, depression, and others. There are many drugs that must not be taken with this drug. Your doctor or pharmacist can tell you if you are taking a drug that must not be taken with this drug.

This is not a list of all drugs or health problems that interact with this drug.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this drug with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take this drug?

• Tell all of your health care providers that you take this drug. This includes your doctors, nurses, pharmacists, and dentists.
• Have blood work checked as you have been told by the doctor. Talk with the doctor.
• This drug may affect certain lab tests. Tell all of your health care providers and lab workers that you take this drug.
• If you have had an abnormal blood test called Antinuclear Antibody Test (ANA test), talk with your doctor.
• If you have myasthenia gravis, talk with your doctor. Myasthenia gravis has gotten worse during treatment with this drug. Call your doctor if signs get worse.
• If you have a defibrillator or pacemaker, talk with your doctor.
• You will need an ECG before starting this drug and during treatment. Talk with your doctor.
• Avoid grapefruit and grapefruit juice.
• Tell your doctor if you have fluid loss, unusual sweating, throwing up, diarrhea, decreased appetite, or unusual thirst.
• This drug may lower sperm counts. This may affect being able to father a child. If you have questions, talk with the doctor.
• Tell your doctor if you are pregnant, plan on getting pregnant, or are breast-feeding. You will need to talk about the benefits and risks to you and the baby.

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Chest pain or pressure.
• Fast or slow heartbeat.
• Severe dizziness or passing out.
• An abnormal heartbeat that is new or worse.
• Blurred eyesight.
• Heart failure has happened with this drug, as well as heart failure that has gotten worse in people who already have it. Tell your doctor if you have heart disease. Call your doctor right away if you have shortness of breath, a big weight gain, a heartbeat that is not normal, or swelling in the arms or legs that is new or worse.
• Low white blood cell counts have rarely happened with this drug. This may lead to a higher chance of getting an infection. Tell your doctor if you have ever had a low white blood cell count. Call your doctor right away if you have signs of infection like fever, chills, or sore throat.

What are some other side effects of this drug?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Feeling dizzy, tired, or weak.
• Upset stomach or throwing up.
• Constipation.
• Change in taste.
• Headache.
• Anxiety.
• Signs of a common cold.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to your national health agency.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

How is this drug best taken?

Use this drug as ordered by your doctor. Read all information given to you. Follow all instructions closely.

All products:

• Take with or without food.
• Keep taking this drug as you have been told by your doctor or other health care provider, even if you feel well.

Long-acting capsules:

• Swallow whole. Do not chew, open, or crush.

What do I do if I miss a dose?

• Skip the missed dose and go back to your normal time.
• Do not take 2 doses at the same time or extra doses.

How do I store and/or throw out this drug?

• Store at room temperature protected from light. Store in a dry place. Do not store in a bathroom.
• Keep lid tightly closed.
• Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
• Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.

General drug facts

• If your symptoms or health problems do not get better or if they become worse, call your doctor.
• Do not share your drugs with others and do not take anyone else’s drugs.
• Some drugs may have another patient information leaflet. If you have any questions about this drug, please talk with your doctor, nurse, pharmacist, or other health care provider.
• Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about this drug, please talk with your doctor, nurse, pharmacist, or other health care provider.
• If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Consumer Information Use and Disclaimer

This generalized information is a limited summary of diagnosis, treatment, and/or medication information. It is not meant to be comprehensive and should be used as a tool to help the user understand and/or assess potential diagnostic and treatment options. It does NOT include all information about conditions, treatments, medications, side effects, or risks that may apply to a specific patient. It is not intended to be medical advice or a substitute for the medical advice, diagnosis, or treatment of a health care provider based on the health care provider’s examination and assessment of a patient’s specific and unique circumstances. Patients must speak with a health care provider for complete information about their health, medical questions, and treatment options, including any risks or benefits regarding use of medications. This information does not endorse any treatments or medications as safe, effective, or approved for treating a specific patient. UpToDate, Inc. and its affiliates disclaim any warranty or liability relating to this information or the use thereof. The use of this information is governed by the Terms of Use, available at https://www.wolterskluwer.com/en/know/clinical-effectiveness-terms.

Last Reviewed Date

2024-05-24

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