Propafenone (oral)

Propafenone is an oral medication considered to be an antiarrhytmic as it affects the impulses sent by the nerves to the heart, preventing heartbeat irregularities like AF (atrial fibrillation) from happening.


What is Propafenone?

Patients who have been diagnosed with atrial fibrillation, a condition where the heart beats in an irregular pattern, but who have no other symptoms of disease in the structure of the heart, may be treated with an antiarrhythmic drug such as Propafenone. This drug, however, has exhibited signs of causing new or worsening heart rhythm problems on some patients, so the patient's condition must be appropriate for a physician to choose to prescribe this drug.

Patients will be prescribed Propafenone in tablet or extended release capsule form, typically with two doses per day to maintain a steady level in the blood and do its job; calm the erratic signals that the cardiac nerve cells are sending, making the rhythm abnormally fast. For this reason, it is of vital importance that patients follow the dose amount and schedule on their prescriptions. Skipping doses is not advised; neither is taking two doses close together because one has been accidentally missed. When in doubt, contact your health care professional for dosage advice.

Patients with atrial fibrillation have an irregular, racing heartbeat pattern and often feel tired or out of breath. They are unable to do exercise and often experience fainting spells and chest pains. Untreated, atrial fibrillation increases the risk of stroke and heart attack. Patients are typically diagnosed after a check of the patient's pulse followed by an ECG (electrocardiogram) reading to exactly show the beats per minute and any pauses or irregularities. At this point, a drug such as Propafenone may be determined to be appropriate for treatment.

How does Propafenone work?

Propafenone is an antiarrhythmic drug that works by slowing down how the cardiac cells conduct signals across their membranes. This dampens the excited cells, that are causing problems by firing signals too quickly and making the heart beat in a fluttered, too fast pattern. Propafenone does not affect the duration of the signal, merely the rate that the signals are sent.

Propafenone is sold under the trade names of Rythmol and Rythmol SR in the United States and has been approved for use since 1997, first in Europe and then worldwide. Because it affects the heart, Propafenone is typically initiated for treatment while the patient is in the hospital under constant monitoring and dosage is adjusted accordingly.

What is atrial fibrillation?

Atrial fibrillation is a condition where the heart beats much faster than normal, causing issues like extreme fatigue, dizzy spells and gasping for breath. Patients may also be able to feel their own heart beating too fast. Other patients experience no symptoms and, in fact, do not know they have the condition until an emergency situation occurs with their heart. The cause of this condition is unknown but may be more common in persons who are hypertensive or already have heart disease in some form. It is also common in diabetic patients as well as asthmatics. Episodes may be triggered by excessive alcohol consumption, obesity, excessive caffeine intake and certain illegal drugs as well as smoking.

Conditions treated

Type of medicine

  • Antiarrhythmic

Side effects

Propafenone directly affects the cells of the heart as well as their action and, by doing so, may also cause unwanted effects that could range from annoying to severe. Not all of the symptoms listed here take place, but if you do experience them, seek medical attention on an immediate basis:

  • Pains in the chest
  • Too slow, too fast or somehow irregular heartbeat
  • Fainting or being light headed or dizzy
  • Gasping for breath
  • Swollen legs or feet
  • Gaining weight
  • Fever
  • Joint pain
  • Chills
  • Weak muscles
  • Shivering

At the beginning of your drug therapy treatment with Propafenone, you may experience the following unwanted effects that will most likely ebb once your system becomes used to the medication. If you experience any of the following symptoms and they are severe or prolonged, check with your physician to see if there are any ways to ease or eliminate them:

  • Taste of metal or bitterness or a change overall
  • Vision that is blurry
  • Diarrhea
  • Constipation
  • Mouth is dry
  • Vomiting, nausea
  • Headache
  • Rash on the skin
  • Extreme fatigue
  • Muscle weakness

There are other side effects that have not been reported or documented that are experienced by some patients. Overall, if you are feeling ill in any way or showing any signs or symptoms of reaction to Propafenone, report these health changes to your medical professional.


Irregularities in the rhythm of the heart are an on-going medical issue in most patients; their heart does not beat normally under any circumstances. Therefore, it is best that Propafenone, when used to treat this condition, is dosed with a size and frequency that ensures a continuous level of the drug in the patient's system. As every patient is different and so are their symptoms, your dose and frequency of Propafenone may be different than what is listed here. Follow your doctor's prescribed dosing amount and schedule; if you have questions, contact the doctor's office or your pharmacist.

Tablet forms of Propafenone are available in 150, 225 and 300 milligram sizes. Extended release capsule forms of Propafenone are available in 225, 325 and 425 milligram doses. Typically, patients who are prescribed the tablet form of Propafenone are indicated for 150 milligrams every eight hours, increased to 225 milligrams every eight hours after a few days of observation to see how the drug affects them. If required, as much as 300 milligrams every eight hours may be directed but no more than this amount.

Patients who are given extended release capsules typically start with a 225 milligram dose every twelve hours at the beginning and are observed for effects, unwanted symptoms and heart beats per minute. After almost a week of observation on this regimen, the dose may be increased to 325 milligrams or 425 milligrams every twelve hours, respectively, to gain the results the physician would like to see as long as the patient is tolerating the drug. Extended release capsules should be taken whole, never chewed, broken or crushed.

As with any medication, follow the instructions given to you by your doctor to the letter; do not increase the size or frequency of the dose for any reason. If a dose of Propafenone is missed, take it as soon as possible without being too close to your next dosing time. Skip the dose you missed if you are too close to doubling your medication. Review and understand the information provided on the leaflet that comes with your prescription. Any questions should be directed to your health care provider or your pharmacist.


Propafenone may not interact with drugs you are currently taking; on the other hand, some medications, foods and substances may affect how effective or how safe this drug is. Therefore, it is of great importance to disclose to your health care provider all of the medications you are currently taking, including over-the-counter and prescription drugs as well as holistic or vitamin supplements.

Any unusual reaction you've experienced during treatment with other drugs or allergies to preservatives, colorings, foods, animals or environments should be discussed with your health care provider prior to your drug therapy with Propafenone. It is very important to let your physician know if you are currently taking the following drugs, as they are known to interact with Propafenone in a negative way:

  • Amisulpride
  • Amifampridine
  • Cisapride
  • Bepridil
  • Dronedarone
  • Ketoconazole
  • Fluconazole
  • Mesoridazine
  • Levomethadyl
  • Nelfinavir
  • Piperaquine
  • Pimozide
  • Posaconazole
  • Saquinavir
  • Ritonavir
  • Sparfloxacin
  • Thioridazine
  • Terfenadine
  • Tipranavir
  • Ziprasidone
  • Vernakalant

The following medications, while they should not be taken in combination with Propafenone, may be necessary to continue for your good health. Adjustments will need to be made to the dose of these drugs, so let your physician know if you currently take:

  • Alfuzosin
  • Ajmaline
  • Acecainide
  • Amitriptyline
  • Amiodarone
  • Anagrelide
  • Amoxapine
  • Aprindine
  • Apomorphine
  • Arsenic Trioxide
  • Aripiprazole
  • Asenapine
  • Artemether
  • Azimilide
  • Astemizole
  • Boceprevir
  • Azithromycin
  • Bupropion
  • Bretylium
  • Ceritinib
  • Buserelin
  • Chloroquine
  • Chloral Hydrate
  • Ciprofloxacin
  • Chlorpromazine
  • Clarithromycin
  • Citalopram
  • Cobicistat
  • Clomipramine
  • Dabrafenib
  • Crizotinib
  • Dasatinib
  • Dasabuvir
  • Delamanid
  • Degarelix
  • Desipramine
  • Delavirdine
  • Dibenzepin
  • Deslorelin
  • Disopyramide
  • Digoxin
  • Dolasetron
  • Dofetilide
  • Donepezil
  • Domperidone
  • Duloxetine
  • Droperidol
  • Eltrombopag
  • Efavirenz
  • Erythromycin
  • Enflurane
  • Etravirine
  • Escitalopram
  • Flecainide
  • Fingolimod
  • Foscarnet
  • Fluoxetine
  • Gemifloxacin
  • Gatifloxacin
  • Goserelin
  • Gonadorelin
  • Halofantrine
  • Granisetron
  • Halothane
  • Haloperidol
  • Hydroquinidine
  • Histrelin
  • Hydroxyzine
  • Hydroxychloroquine
  • Idelalisib
  • Ibutilide
  • Imipramine
  • Iloperidone
  • Isradipine
  • Isoflurane
  • Lapatinib
  • Ivabradine
  • Levofloxacin
  • Leuprolide
  • Lidoflazine
  • Lidocaine
  • Lorcainide
  • Lopinavir
  • Mefloquine
  • Lumefantrine
  • Metronidazole
  • Methadone
  • Mirabegron
  • Mifepristone
  • Moxifloxacin
  • Mirtazapine
  • Nilotinib
  • Nafarelin
  • Nortriptyline
  • Norfloxacin
  • Ombitasvir
  • Octreotide
  • Paliperidone
  • Ondansetron
  • Paritaprevir
  • Panobinostat
  • Pasireotide
  • Paroxetine
  • Pentamidine
  • Pazopanib
  • Pimavanserin
  • Perflutren Lipid Microsphere
  • Pitolisant
  • Pirmenol
  • Prilocaine
  • Prajmaline
  • Procainamide
  • Probucol
  • Promethazine
  • Prochlorperazine
  • Protriptyline
  • Propafenone
  • Quinidine
  • Quetiapine
  • Ranolazine
  • Quinine
  • Salmeterol
  • Risperidone
  • Sertindole
  • Simeprevir
  • Sertraline
  • Sematilide
  • Sevoflurane
  • Solifenacin
  • Sodium Phosphate, Dibasic or Monobasic
  • Sorafenib
  • Spiramycin
  • Sotalol
  • Sulfamethoxazole
  • Sultopride
  • Sulpiride
  • Sunitinib
  • Tedisamil
  • Tacrolimus
  • Telaprevir
  • Tetrabenazine
  • Telithromycin
  • Tizanidine
  • Trazodone
  • Toremifene
  • Trifluoperazine
  • Trimipramine
  • Trimethoprim
  • Triptorelin
  • Vandetanib
  • Vasopressin
  • Vardenafil
  • Vemurafenib
  • Voriconazole
  • Vinflunine
  • Zolmitriptan
  • Zuclopenthixol
  • Zotepine

The following drugs also interact in a negative way with Propafenone, but the use of both medications may be mandatory for your health. Your physician will want to know if you currently take?

  • Tolterodine
  • Rifapentine
  • Cyclosporine
  • Rifampin
  • Theophylline
  • Warfarin

It is up to the tolerance of your own system whether you take this drug with food or not; however, certain types of food or beverages can cause unwanted effects as well. Avoid grapefruit juice while taking this medication as well as the use of tobacco in any way, as they may cause unwanted side effects during your treatment with Propafenone.

Similarly, the presence of medical conditions, either diagnosed or suspected, can also affect how Propafenone works on your atrial fibrillation symptoms or what side effects you experience. Notify your physician immediately if you have been diagnosed with or experience the symptoms of the following medical conditions:


With regard to the age of the patient, Propafenone has not been the part of any study that has provided data on pediatric use. Therefore, use in this age group is not recommended. Geriatric patients have also not been part of any data-gathering as to the safety or effectiveness of Propafenone. This age group should be monitored closely if prescribed Propafenone, with their personal physicians determining whether this treatment is appropriate and safe.

No studies have been performed on pregnant women to determine if Propafenone places the fetus at risk for birth defects. This risk should be weighed to determine if drug therapy with Propafenone is appropriate, but it is not recommended in this instance. Limited data with regards to breastfeeding women demonstrates the passing of Propafenone in certain amounts through the breastmilk to the child. Therefore, extreme caution should be used before deciding on a treatment regimen of Propafenone in nursing mothers.

Propafenone has been known to affect breathing in certain patients, so those with lung infections or conditions such as asthma, emphysema or bronchitis should only be prescribed Propafenone under caution. The same caution applies to patients who have permanent pacemakers installed, as Propafenone can interfere with the device.

Patients are cautioned to always take extended release capsules of Propafenone whole, without breaking them, crushing them or chewing them up, as this defeats the purpose of the extended release of the medication in your body, which is required for a good result. Avoid grapefruit juice and tobacco use while on this medication as both can lead to unsafe levels of Propafenone in your blood stream.

As Propafenone can cause vision to be blurred, fatigue, hypotension and dizzy spells, it is not advised that patients drive or operate power tools or machinery while being treated with this medication.


Propafenone, whether in tablet or extended release capsule form, should be stored out of sight and reach of children and pets in the original container, kept closed with the child-proof cap provided for safety. Keep Propafenone at room temperature and away from heat, moisture and light. Do not allow this medication to freeze.

Disposal of this medication, should you have unused or expired product, should be done under the advisement of your health care professional or pharmacist for safety purposes. Take only as prescribed by your doctor, who should be contacted immediately if you have any questions. You may be able to donate unexpired, unused doses of this medication to charitable agencies. Your physician or pharmacist will have information and instructions on how to make this medical donation, if possible.


Propafenone is an antiarrhythmic prescription drug that is appropriate for treatment of atrial fibrillation (AF) in most patients. Propafenone works by directly affecting the nerve cells in the heart, calming their erratic, too fast impulses and leveling off the heartbeat to a normal rhythm. Propafenone is available in tablet and extended release capsule form.

Typically, patients are under doctor supervision in a hospital setting when given the initial dose of Propafenone so that the effects, both good and bad, can be observed and emergency care is available if necessary. Each patient is different and, therefore, so is their prescription of Propafenone. In general, patients prescribed tablet forms received 150 milligrams every eight hours, to be adjusted by doctors from there. Patients who receive the extended-release form of Propafenone are initially given 225 milligrams every 12 hours, which is adjusted by doctors appropriately.

Side effects, while different for every patient, typically involve fatigue, blurry vision, dizzy and fainting spells, headaches, constipation or vomiting and nausea. Serious effects involving pains in the chest or irregular heartbeats should prompt the patient to seek medical care on an emergency basis. Patients with breathing issues or other cardiac issues including permanent pacemakers should only be prescribed Propafenone on a cautionary basis.

Multiple drugs interact with Propafenone but may be necessary to use at the same time for health reasons. Because of this, it is advised that you disclose any drugs you may be taking before receiving a dose of Propafenone and include any vitamins, herbs or non-prescription medications as well. Other medical conditions can be worsened by treatment with Propafenone; communicate your full medical history to your health care professional to make sure you are safe to take this drug.

Propafenone may cause serious irregularities in heart rhythm which can be fatal or cause blockages in the heart. Because of this, patients are typically first started on Propafenone in a hospital setting where they can be monitored for the drug's effects on their heart rhythms.

Patients are able to store Propafenone at room temperature but are cautioned to use the child proof container the prescription comes in and keep it out of sight and reach of children and pets. Dispose of Propafenone safely according to instructions from your physician or pharmacist.

Last Reviewed:
February 02, 2018
Last Updated:
April 10, 2018