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propafenone

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Brand names: Rythmol

Class IC Antiarrhythmic Rx

Propafenone (Rythmol) is a medicine that helps control irregular heartbeats. It works by slowing down electrical signals in the heart.

Drug Shortage Alert

propafenone is currently listed as to be discontinued by the FDA. Affected manufacturer: Upsher-Smith Laboratories, LLC.

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Drug Pricing (NADAC)

Generic Price

$0.12/unit

Generic Available

Yes (11 manufacturers)

Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →

What it does

This medicine is used to help keep your heart rhythm normal if you have atrial fibrillation or supraventricular tachycardia.

Common side effects

Unusual taste, Nausea, Vomiting

Key warnings

This medicine may increase the risk of death in people with heart problems.

How It Works

Propafenone works by affecting the electrical activity in your heart. It slows down the signals that cause irregular heartbeats. This helps your heart beat more regularly.

How to Take It

Take this medicine exactly as your doctor tells you. You will usually start with 150 mg every 8 hours. Your doctor may increase the dose every 3 to 4 days up to 300 mg every 8 hours as needed. If you have liver problems, your doctor may prescribe a lower dose.

Pregnancy & Breastfeeding

Tell your doctor if you are pregnant or plan to become pregnant. This medicine can cross the placenta, and may affect the baby. Your doctor will monitor you and your baby for any problems.

Missed Dose

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule.

Storage

Store at room temperature, away from light and moisture.

Side Effects (from patient reports)

Based on 2,484 FDA adverse event reports.

Irregular heartbeat in the upper chambers of the heart
347
Medicine not working
330
Medicine interacting with another medicine
320
Feeling lightheaded or unsteady
261
Harmful effect from different substances
231
Shortness of breath
226
Feeling sick to your stomach
205
Feeling tired
201
Using the medicine for a purpose not approved
182
Weakness
181

FDA Adverse Event Report Analysis

Detailed analysis of 4,113 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.

Total Reports

4,113

Death-Related Reports

483

Hospitalization Reports

1,763

Top Indication

Product Used For Unknown Indication

Gender Distribution

Female 2,197 (58%)
Male 1,568 (41%)

Age Distribution

0–17 104
18–44 214
45–64 764
65–74 1,001
75+ 1,019

Most Reported Adverse Reactions (FAERS)

# Reaction Reports
1 ATRIAL FIBRILLATION 347
2 DRUG INEFFECTIVE 330
3 DRUG INTERACTION 320
4 DIZZINESS 262
5 TOXICITY TO VARIOUS AGENTS 231
6 DYSPNOEA 226
7 NAUSEA 206
8 FATIGUE 201
9 OFF LABEL USE 182
10 ASTHENIA 181
11 BRADYCARDIA 168
12 HYPOTENSION 164
13 DIARRHOEA 143
14 FALL 142
15 ARRHYTHMIA 137

Reactions in Death Reports

COMPLETED SUICIDE 114
DEATH 87
TOXICITY TO VARIOUS AGENTS 61
DRUG INTERACTION 46
CARDIAC ARREST 40
ACUTE KIDNEY INJURY 32
SUBARACHNOID HAEMORRHAGE 29
ELECTROCARDIOGRAM QRS COMPLEX PROLONGED 27
LOSS OF CONSCIOUSNESS 26
HYPOTENSION 25

Reactions in Hospitalization Reports

ATRIAL FIBRILLATION 194
DRUG INTERACTION 158
TOXICITY TO VARIOUS AGENTS 151
DYSPNOEA 124
DRUG INEFFECTIVE 116
NAUSEA 109
BRADYCARDIA 108
DIZZINESS 107
ASTHENIA 105
HYPOTENSION 102

Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation

Serious Warnings

This medicine may increase the risk of death in people with heart problems. Do not take this medicine if you have structural heart disease and non-life-threatening ventricular arrhythmias. Talk to your doctor about the risks and benefits of taking this medicine.

Known Drug Interactions

Antiarrhythmics amiodarone, dronedarone, flecainide, propafenone, quinidine ↑ antiarrhythmic Co-administration contraindicated due to potential for cardiac arrhythmias [see Contraindications (4) ] .

Mechanism: Taking these together causes propafenone to stay in your body longer and reach higher levels than intended. This can lead to serious and potentially fatal heart rhythm disturbances.

What to do: Do not take these medications together. Consult your doctor to manage your heart condition with a safer treatment option.

moderate amiodarone

Amiodarone Concomitant administration of propafenone and amiodarone can affect conduction and repolarization and is not recommended.

Mechanism: Taking these two heart medicines together can change how electrical signals travel through your heart. This can interfere with your heart's rhythm and how it resets between beats.

What to do: This combination is generally not recommended. Talk to your doctor about safer alternatives for managing your heart rhythm.

moderate fluoxetine

Coadministration of fluoxetine with other drugs that are metabolized by CYP2D6, including certain antidepressants (e.g., TCAs), antipsychotics (e.g., phenothiazines and most atypicals), and antiarrhythmics (e.g., propafenone, flecainide, and others) should be approached with caution. Drugs with a narrow therapeutic index represent the greatest concern (e.g., flecainide, propafenone, vinblastine, and TCAs).

Mechanism: Fluoxetine slows down how fast your body processes propafenone. This can lead to higher amounts of the heart medicine in your system than intended.

What to do: This combination should be used with caution. Your doctor should monitor you closely for side effects or adjust your medication levels.

moderate nebivolol

( 7.4 ) 7.1 CYP2D6 Inhibitors Use caution when nebivolol is co-administered with CYP2D6 inhibitors (quinidine, propafenone, fluoxetine, paroxetine, etc.) [ see Clinical Pharmacology ( 12.5 ) ].

Mechanism: Propafenone slows down the body's ability to process nebivolol, which could cause the medication to build up to higher levels.

What to do: Use caution when taking these drugs together and consult your doctor about potential dose adjustments.

(7.6) 7.1 CYP2D6 and CYP3A4 Inhibitors Drugs that inhibit CYP2D6 (such as desipramine, paroxetine, ritonavir, sertraline) and CYP3A4 (such as ketoconazole, ritonavir, saquinavir, erythromycin, grapefruit juice) can be expected to cause increased plasma levels of propafenone.

Mechanism: Ketoconazole slows down the liver's ability to break down propafenone, which can cause the drug to build up in your body.

What to do: Your doctor may need to adjust your dose or monitor you more closely for side effects.

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Common Questions

Can I take this medicine if I have heart failure?
No, you should not take this medicine if you have heart failure.
Can I take this medicine if I have a pacemaker?
This medicine may affect artificial pacemakers. Your doctor will monitor your pacemaker function.
What should I do if I feel dizzy after taking this medicine?
Dizziness is a common side effect. If you feel dizzy, sit or lie down until the feeling passes.
Can I drink grapefruit juice while taking this medicine?
No, avoid grapefruit juice while taking this medicine. It can increase the level of propafenone in your blood.
What if I develop an infection while taking this medicine?
Tell your doctor right away if you develop signs of infection, such as fever, sore throat, or chills.
Can this medicine worsen my myasthenia gravis?
Yes, this medicine may make myasthenia gravis worse.
Can I take this with other heart medicines?
Tell your doctor about all the medicines you take, including heart medicines, before starting propafenone.
What if my heart rhythm gets worse on this medicine?
This medicine can sometimes cause new or worsened arrhythmias. Your doctor will monitor you with ECGs.
Can this medicine affect my blood pressure?
This medicine can cause low blood pressure. Tell your doctor if you feel lightheaded or dizzy.
Is it safe to take propafenone while breastfeeding?
Talk to your doctor about the risks and benefits of taking propafenone while breastfeeding.
What are the common side effects of propafenone?
The most commonly reported side effects of propafenone include Unusual taste, Nausea, Vomiting, Dizziness, Constipation. Based on 2,484 FDA adverse event reports. Always consult your healthcare provider about potential side effects.
Does propafenone interact with other medications?
Yes, propafenone has 26 known drug interactions. Notable interactions include nirmatrelvir/ritonavir, amiodarone, fluoxetine. Always inform your doctor about all medications you are taking.
What drug class is propafenone?
propafenone belongs to the Class IC Antiarrhythmic drug class. It requires a prescription (Rx). This medicine is used to help keep your heart rhythm normal if you have atrial fibrillation or supraventricular tachycardia.
Is propafenone safe during pregnancy?
Tell your doctor if you are pregnant or plan to become pregnant. This medicine can cross the placenta, and may affect the baby. Always consult your healthcare provider before using any medication during pregnancy or breastfeeding.
Has propafenone been recalled?
There is 1 recall associated with propafenone products. CGMP Deviations. Check the recalls section below for full details and affected products.
Is propafenone currently in shortage?
Yes, propafenone is currently listed as to be discontinued by the FDA. Affected manufacturer: Upsher-Smith Laboratories, LLC. Visit the FDA Drug Shortages database for the latest updates.

Active Recalls

Class II March 13, 2025

CGMP Deviations

Glenmark Pharmaceuticals Inc., USA

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What the FDA Data Shows for propafenone

The FDA label for propafenone (sold under brand names such as Rythmol) classifies it as a prescription-only medication in the Class IC Antiarrhythmic class. This medicine is used to help keep your heart rhythm normal if you have atrial fibrillation or supraventricular tachycardia. Official labeling lists 9 commonly reported side effects, including Unusual taste, Nausea, Vomiting.

Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 2,484 voluntary reports. The database also lists 26 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated major severity. NADAC pricing from CMS shows a generic unit cost of $0.12.

Report counts do not establish causation — a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 1 recall record on file), and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice — always consult a licensed healthcare provider before starting, stopping, or changing any medication.

Data Sources

Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC). Shortage status: FDA Drug Shortages Database.

FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.

Last updated: July 21, 2023

All federal data sources used on this page