Prescription medication · Class III Antiarrhythmic
dofetilide
Also sold as Tikosyn. This medicine is used to maintain a normal heart rhythm if you have atrial fibrillation or atrial flutter for more than a week, and your heart has been returned to a normal rhythm.
Data updated 2026-05-15
- 10,302
- FDA reportsModerately reported
- 8
- InteractionsFew interactions
- 98% less
- Generic vs brandHuge savings
- $10.66
- Brand price (NADAC)
What the data shows
dofetilide (Tikosyn) is a prescription Class III Antiarrhythmic, reported less often than most tracked drugs (10,302 FDA reports), whose generic costs a fraction of the brand (about 98% less).
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.
dofetilide (Tikosyn) is a prescription Class III Antiarrhythmic. This medicine is used to maintain a normal heart rhythm if you have atrial fibrillation or atrial flutter for more than a week, and your heart has been returned to a normal rhythm.
Dofetilide (Tikosyn) helps keep your heart in a normal rhythm if you have atrial fibrillation or atrial flutter. It can also help convert these abnormal rhythms back to normal.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Brand Price
$10.66/unit
Generic Price
$0.19/unit
Generic Savings
98%
Generic Available
Yes (8 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
NADAC price trail: DOFETILIDE 125 MCG CAPSULE
Same CMS presentation as the headline generic unit price above (2 effective dates). Adjacent % compares consecutive NADAC releases for this description only, not a patient out-of-pocket quote. Latest step: -16.3% vs prior release.
| Effective | NADAC / unit | vs prior | NDCs |
|---|---|---|---|
| March 20, 2024 | $0.2306/EA | - | 1 |
| December 18, 2024 | $0.1931/EA | -16.3% | 10 |
What it does
This medicine is used to maintain a normal heart rhythm if you have atrial fibrillation or atrial flutter for more than a week, and your heart has been returned to a normal rhythm.
Common side effects
Headache, Chest pain, Dizziness
Key warnings
This drug can cause life-threatening heart rhythm problems.
The sections below are summarized in plain English from dofetilide's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Dofetilide belongs to a class of drugs called Class III antiarrhythmics. It works by changing the electrical activity in your heart. This helps to stabilize your heart rhythm and prevent irregular heartbeats.
Side Effects (from patient reports)
Based on 10,302 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for dofetilide, by number of reports
- Atrial Fibrillation
Atrial Fibrillation
1,058 reports
- Dyspnoea
Dyspnoea
603 reports
- Dizziness
Dizziness
552 reports
- Fatigue
Fatigue
520 reports
- Death
Death
478 reports
- Electrocardiogram Qt Prolonged
Electrocardiogram Qt Prolonged
443 reports
- Headache 387
Headache
387 reports
- Malaise 319
Malaise
319 reports
- Diarrhoea 316
Diarrhoea
316 reports
- Drug Interaction 297
Drug Interaction
297 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 dofetilide 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 dofetilide sits
dofetilide has more FDA adverse-event reports than 40% 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 dofetilide; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 10,302 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.
Total Reports
10,302
Reports Mentioning Death
799
7.8% of reports — not proof of cause
Hospitalization Reports
2,960
Top Indication
Atrial Fibrillation
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | ATRIAL FIBRILLATION | 1,058 |
| 3 | DYSPNOEA | 603 |
| 4 | DIZZINESS | 552 |
| 5 | FATIGUE | 520 |
| 6 | DEATH | 478 |
| 7 | ELECTROCARDIOGRAM QT PROLONGED | 443 |
| 8 | HEADACHE | 387 |
| 9 | MALAISE | 319 |
| 10 | DIARRHOEA | 316 |
| 11 | DRUG INTERACTION | 297 |
| 12 | NAUSEA | 288 |
| 13 | HEART RATE INCREASED | 286 |
| 14 | ASTHENIA | 285 |
| 15 | ARRHYTHMIA | 265 |
| 16 | CARDIAC DISORDER | 248 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
This drug can cause life-threatening heart rhythm problems. To lower this risk, you must start or restart this medicine in a hospital where your heart can be watched closely for at least 3 days. The hospital staff will check your kidney function and heart rhythm regularly.
Known Drug Interactions
Coadministration of BIKTARVY with drugs that are substrates of OCT2 and MATE1 (e.g., dofetilide) may increase their plasma concentrations (see Table 3 ). Clinical Comment Antiarrhythmics: dofetilide ↑ Dofetilide Coadministration is contraindicated due to the potential for serious and/or life-threatening events associated with dofetilide therapy [see Contraindications (4) ] .
Mechanism: The HIV medicine blocks the way your body removes the heart medicine dofetilide, causing it to build up to dangerous levels. High levels of dofetilide can cause life-threatening heart rhythm problems.
Dolutegravir may increase plasma concentrations of drugs eliminated via OCT2 or MATE1 (dofetilide, dalfampridine, and metformin) [see Contraindications ( 4 ), Drug Interactions ( 7.3 )] . Other Agents Antiarrhythmic: Dofetilide ↑Dofetilide Coadministration is contraindicated with TRIUMEQ and TRIUMEQ PD [see Contraindications ( 4 )] .
Mechanism: Dolutegravir blocks the proteins in the kidneys that normally help remove dofetilide from the body. This causes the levels of dofetilide in your blood to rise.
7.2 Potential for DOVATO to Affect Other Drugs Dolutegravir, a component of DOVATO, inhibits the renal organic cation transporters (OCT)2 and multidrug and toxin extrusion transporter (MATE)1; thus, it may increase plasma concentrations of drugs eliminated via OCT2 or MATE1 such as dofetilide, dalfampridine, and metformin [see Contraindications ( 4 ), Drug Interactions ( 7.4 ), Clinical Pharmacology ( 12.3 )]. Coadministered Drug Class: Drug Name Effect on Concentration Clinical Comment Antiarrhythmic: Dofetilide ↑Dofetilide Coadministration is contraindicated with DOVATO [see...
Mechanism: One of the medicines in this combination blocks the pathways your kidneys use to get rid of dofetilide. This can lead to dangerously high levels of dofetilide in your system.
Antiarrhythmics Disopyramide Dofetilide Dronedarone Quinidine a Contraindicated during and 2 weeks after itraconazole treatment.
Mechanism: Itraconazole interferes with the way your body breaks down dofetilide, potentially causing the heart medication to reach dangerous levels.
Clinically Significant Drug Interactions with Clarithromycin Tablets Drugs That Are Affected By Clarithromycin Tablets Drug(s) with Pharmacokinetics Affected by Clarithromycin Tablets Recommendation Comments Antiarrhythmics: Disopyramide Quinidine Dofetilide Amiodarone Sotalol Procainamide Not Recommended Disopyramide, Quinidine: There have been postmarketing reports of torsades de pointes occurring with concurrent use of clarithromycin and quinidine or disopyramide.
Mechanism: Clarithromycin affects how this heart medicine is broken down, which can increase the risk of a life-threatening irregular heartbeat.
This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.
Common Questions
What should I do if I feel dizzy after taking this medicine?
Can I drink alcohol while taking this medicine?
Will this medicine cure my atrial fibrillation?
How often will I need to see my doctor while taking this medicine?
Can I take other medicines with dofetilide?
What if I have kidney problems?
What if my heart rate is slow?
How long will I need to take this medicine?
What are the signs of Torsade de Pointes?
Can I stop taking this medicine on my own?
What are the common side effects of dofetilide?
Does dofetilide interact with other medications?
What drug class is dofetilide?
Is there a generic version of dofetilide?
What pregnancy or breastfeeding source fields are listed for dofetilide?
Related Medications in Class III Antiarrhythmic
Other drugs grouped near dofetilide - same-class peers and common alternatives.
adenosine
Adenocard
Adenosine (Adenocard) is a medicine used to treat certain types of irregular heartbeats.
Compare with dofetilide →
amiodarone
Cordarone, Pacerone
Amiodarone (Pacerone) is a medicine used to treat life-threatening, irregular heartbeats.
Compare with dofetilide →
atropine
AtroPen
Atropine is a medicine that can temporarily block severe effects on your body.
Compare with dofetilide →
bumetanide
Bumex
Bumetanide is a water pill (diuretic).
Compare with dofetilide →
carvedilol
Coreg
Carvedilol is a medicine that lowers blood pressure and helps your heart work better.
Compare with dofetilide →
Compare beyond drug class
Nationwide peers by FAERS volume & death-report share
Two PlainMeds-derived comparison paths for dofetilide: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.
Similar FAERS report volume
Nearest drugs by total FAERS reports. This record: 10,302.
Similar death-report share
Nearest drugs by FAERS death-report share. This record: 7.76%.
- methocarbamol Δ 0.00 pts · 21,191 reports · Muscle Relaxant 7.75%death share
- cannabidiol Δ 0.01 pts · 22,227 reports · Cannabinoid (Anticonvulsant) 7.77%death share
- cefdinir Δ 0.02 pts · 7,348 reports · Third-Generation Cephalosporin 7.77%death share
- etodolac Δ 0.05 pts · 5,880 reports · Nonsteroidal Anti-Inflammatory Drug (NSAID) 7.81%death share
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
FDA bioequivalence and label-record context for narrow therapeutic index medicines
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
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What the FDA Data Shows for dofetilide
The FDA label for dofetilide (sold under brand names such as Tikosyn) classifies it as a prescription-only medication in the Class III Antiarrhythmic class. This medicine is used to maintain a normal heart rhythm if you have atrial fibrillation or atrial flutter for more than a week, and your heart has been returned to a normal rhythm. Official labeling lists 3 commonly reported side effects, including Headache, Chest pain, Dizziness.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 10,302 voluntary reports. The database also lists 8 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 $0.19 versus $10.66 for the brand - a 98% generic savings.
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, and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.
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).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.
Last updated: February 9, 2025
PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.
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 from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.
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