Prescription medication · Class IC Antiarrhythmic
propafenone
Also sold as Rythmol. This medicine is used to help keep your heart rhythm normal if you have atrial fibrillation or supraventricular tachycardia.
Data updated 2026-05-15
- 4,113
- FDA reportsLightly reported
- 26
- InteractionsSeveral interactions
- In shortage
- FDA status
What the data shows
propafenone (Rythmol) is a prescription Class IC Antiarrhythmic, among the least-reported drugs the FDA tracks (4,113 FDA reports), with 26 documented drug interactions.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
propafenone (Rythmol) is a prescription Class IC Antiarrhythmic. This medicine is used to help keep your heart rhythm normal if you have atrial fibrillation or supraventricular tachycardia.
Propafenone (Rythmol) is a medicine that helps control irregular heartbeats. It works by slowing down electrical signals in the heart.
Verify with FDA → · CMS NADAC pricing →
Drug Shortage Alert
propafenone is currently listed as to be discontinued by the FDA. Affected manufacturer: Upsher-Smith Laboratories, LLC.
View all drug shortages →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.
The sections below are summarized in plain English from propafenone's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
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.
This is a plain-language summary of propafenone's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
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.
This is a plain-language summary of propafenone's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
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.
This is a plain-language summary of propafenone's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store at room temperature, away from light and moisture.
Side Effects (from patient reports)
Based on 4,113 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for propafenone, by number of reports
- Irregular heartbeat in the upper chambers of the heart
Irregular heartbeat in the upper chambers of the heart
347 reports
- Medicine interacting with another medicine
Medicine interacting with another medicine
320 reports
- Feeling lightheaded or unsteady
Feeling lightheaded or unsteady
261 reports
- Harmful effect from different substances
Harmful effect from different substances
231 reports
- Shortness of breath
Shortness of breath
226 reports
- Feeling sick to your stomach
Feeling sick to your stomach
205 reports
- Feeling tired
Feeling tired
201 reports
- Weakness
Weakness
181 reports
- Slow heart rate
Slow heart rate
169 reports
- Low blood pressure
Low blood pressure
164 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for propafenone each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where propafenone sits
propafenone has more FDA adverse-event reports than 23% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is propafenone; the line is the median (50th percentile).
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
Reports Mentioning Death
483
11.7% of reports — not proof of cause
Hospitalization Reports
1,763
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | ATRIAL FIBRILLATION | 347 |
| 3 | DRUG INTERACTION | 320 |
| 4 | DIZZINESS | 262 |
| 5 | TOXICITY TO VARIOUS AGENTS | 231 |
| 6 | DYSPNOEA | 226 |
| 7 | NAUSEA | 206 |
| 8 | FATIGUE | 201 |
| 10 | ASTHENIA | 181 |
| 11 | BRADYCARDIA | 168 |
| 12 | HYPOTENSION | 164 |
| 13 | DIARRHOEA | 143 |
| 14 | FALL | 142 |
| 15 | ARRHYTHMIA | 137 |
| 16 | CARDIAC ARREST | 127 |
| 17 | ELECTROCARDIOGRAM QRS COMPLEX PROLONGED | 125 |
Reactions in Death Reports
Reactions in Hospitalization Reports
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.
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.
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.
( 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.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
Common Questions
Can I take this medicine if I have heart failure?
Can I take this medicine if I have a pacemaker?
What should I do if I feel dizzy after taking this medicine?
Can I drink grapefruit juice while taking this medicine?
What if I develop an infection while taking this medicine?
Can this medicine worsen my myasthenia gravis?
Can I take this with other heart medicines?
What if my heart rhythm gets worse on this medicine?
Can this medicine affect my blood pressure?
Is it safe to take propafenone while breastfeeding?
What are the common side effects of propafenone?
Does propafenone interact with other medications?
What drug class is propafenone?
Is propafenone safe during pregnancy?
Has propafenone been recalled?
Is propafenone currently in shortage?
Active Recalls
CGMP Deviations
Glenmark Pharmaceuticals Inc., USA
Related Medications in Class IC Antiarrhythmic
Other drugs grouped near propafenone - same-class peers and common alternatives.
adenosine
Adenocard
Adenosine (Adenocard) is a medicine used to treat certain types of irregular heartbeats.
Compare with propafenone →
amiodarone
Cordarone, Pacerone
Amiodarone (Pacerone) is a medicine used to treat life-threatening, irregular heartbeats.
Compare with propafenone →
atropine
AtroPen
Atropine is a medicine that can temporarily block severe effects on your body.
Compare with propafenone →
bumetanide
Bumex
Bumetanide is a water pill (diuretic).
Compare with propafenone →
carvedilol
Coreg
Carvedilol is a medicine that lowers blood pressure and helps your heart work better.
Compare with propafenone →
Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
Why some drugs demand precise dosing and monitoring
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
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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 4,113 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
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages