Flecainide
| Evidence Level: L2 | Predicted Indications: 10 |
Table of Contents
Flecainide: From Atrial Fibrillation to Stroke Disorder
One-Sentence Summary
Flecainide is a Class Ic antiarrhythmic originally used to control cardiac rhythm in atrial fibrillation/flutter and paroxysmal supraventricular tachycardia. The TxGNN model predicts it may be relevant to Stroke Disorder, with 19 clinical trials and 20 publications identified — but the link is indirect (via AF rhythm control rather than a direct antithrombotic or neuroprotective mechanism), and the drug is not currently marketed in Taiwan.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Cardiac arrhythmia — atrial fibrillation/flutter, paroxysmal SVT (rhythm control), per known drug classification |
| Predicted New Indication | Stroke disorder |
| TxGNN Prediction Score | 99.91% |
| Evidence Level | L2 |
| Taiwan Market Status | ✗ Not Marketed (Not marketed) |
| Number of Registrations | 0 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data for flecainide is not available in this evidence pack (flagged as a High-severity data gap). Based on well-established pharmacological knowledge, flecainide is a Class Ic antiarrhythmic that blocks the fast cardiac sodium channel (Nav1.5), slowing conduction in atrial and ventricular myocardium. Its proven efficacy is in rhythm control for atrial fibrillation (AF), atrial flutter, and paroxysmal supraventricular tachycardia.
AF is a well-known major risk factor for ischemic stroke, increasing risk roughly five-fold. The mechanistic rationale for this prediction is therefore indirect: by suppressing AF and maintaining sinus rhythm, flecainide could theoretically reduce the burden of atrial arrhythmia that predisposes to thromboembolic stroke — not through a direct antithrombotic or cerebrovascular mechanism.
This rationale requires caution. Large historical trials (e.g., AFFIRM) did not show that a rhythm-control strategy clearly outperforms rate control for reducing stroke specifically, and Class Ic agents carry a well-documented proarrhythmic risk (notably informed by the CAST trial in structural heart disease). The strongest supporting evidence here — the EAST-AFNET 4 trial (PMID 38702961) — used flecainide as one of several sodium-channel blockers in an early comprehensive rhythm-control strategy, not as a stroke-specific intervention. This nuance should be weighed carefully before advancing the candidate.
Clinical Trial Evidence
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT05293080 | Phase 3 | Not yet recruiting | 1746 | Tests whether early, comprehensive rhythm-control therapy prevents adverse cardiovascular outcomes in patients with acute ischemic stroke and AF vs. usual care |
| NCT05213104 | Phase 3 | Active, not recruiting | 186 | Assesses whether flecainide after PFO closure lowers the risk of atrial arrhythmia/tachycardia in cryptogenic stroke patients |
| NCT00911508 | N/A | Completed | 2204 | CABANA trial: catheter ablation vs. antiarrhythmic drug (rate/rhythm control) therapy for AF; large completed pivotal trial |
| NCT06783868 | N/A | Not yet recruiting | 100 | SAVE STROKE Phase II: neurological outcomes after AF ablation vs. routine medication in patients with recent stroke |
| NCT07405671 | Phase 4 | Not yet recruiting | 988 | Evaluates flecainide safety vs. standard rhythm-control drugs (sotalol/amiodarone) in AF patients with stable coronary artery disease |
| NCT01646281 | Phase 4 | Unknown | 70 | Compares vernakalant vs. flecainide effects on atrial contractility in AF, a factor linked to stroke risk |
| NCT03737929 | N/A | Recruiting | 228 | Hybrid ablative therapy vs. conventional catheter ablation for persistent AF |
| NCT07270848 | Phase 4 | Not yet recruiting | 1898 | Dronedarone for early rhythm control in AF (comparator antiarrhythmic study, not flecainide-specific) |
| NCT01447862 | Phase 4 | Completed | 101 | Vernakalant vs. ibutilide for conversion of recent-onset AF |
| NCT05939076 | Phase 3 | Not yet recruiting | 220 | Cryoballoon pulmonary vein isolation vs. antiarrhythmic drugs as first-line therapy for persistent AF |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 38702961 | 2024 | RCT (EAST-AFNET 4 analysis) | Europace | Long-term safety/efficacy of sodium channel blockers (flecainide, propafenone) in early rhythm control; addresses proarrhythmic concerns in cardiovascular disease |
| 28496906 | 2013 | Cohort | Journal of Atrial Fibrillation | Real-world cohort comparing risk of cardiovascular events, stroke, and heart failure across dronedarone, amiodarone, and other antiarrhythmics |
| 27159789 | 2016 | Review | Nature Reviews Disease Primers | Comprehensive AF review identifying stroke as a key complication and discussing rate/rhythm control management |
| 39077579 | 2023 | Review | Reviews in Cardiovascular Medicine | Management of AF during pregnancy, including antiarrhythmic drug risk-benefit considerations |
| 35114252 | 2022 | Basic/mechanistic | Journal of Molecular and Cellular Cardiology | Biophysical basis for flecainide’s atrial-selective efficacy and relative ventricular safety |
| 37109225 | 2023 | RCT (pilot) | Journal of Clinical Medicine | Multicenter randomized open-label pilot comparing carvedilol vs. flecainide for suppressing idiopathic ventricular premature complexes |
| 25430048 | 2014 | Review | BMJ Clinical Evidence | Acute AF management review; notes increased risk of stroke and heart failure |
| 21718559 | 2011 | Review | BMJ Clinical Evidence | Earlier edition of acute AF management review, same stroke/heart failure risk context |
| 19450312 | 2008 | Review | BMJ Clinical Evidence | Earliest edition of acute AF review; AF increases stroke and heart failure risk |
| 40800559 | 2025 | Case report | European Heart Journal - Case Reports | Rare case of refractory ventricular tachycardia (“flecainide fallout”), highlighting proarrhythmic risk in structural heart disease |
Taiwan Market Information
Flecainide is currently not marketed in Taiwan — there are no registered product licenses on file (0 total licenses).
Safety Considerations
Drug Interactions: 215 total interactions on file. Notable examples include:
- Major: Dolasetron, Eliglustat
- Moderate: Famotidine, Loperamide, Bupropion, Lorcaserin, Bisacodyl, Cimetidine, Clarithromycin, Picosulfuric acid, Polyethylene glycol (3350 with electrolytes), Palonosetron, Trospium, Sodium sulfate, Levofloxacin, Lactitol, Lactulose
- Minor: Ascorbic acid, Potassium citrate, Metronidazole
Key warnings and contraindications from the local package insert are not yet available in this dataset (data gap, Blocking severity) — this must be resolved before any safety pre-assessment can proceed.
Conclusion and Next Steps
Decision: Hold
Rationale: A Blocking-severity data gap (missing TFDA label warnings/contraindications) prevents even an initial safety assessment, and the drug is not currently marketed in Taiwan. While evidence level L2 is supported by the EAST-AFNET 4 RCT, the link to “stroke disorder” is indirect — mediated through AF rhythm control rather than a direct stroke-specific mechanism — and flecainide’s known proarrhythmic risk in structural heart disease warrants caution.
To proceed, the following is needed:
- Official TFDA/manufacturer package insert data (warnings, contraindications) to complete the S1 safety pre-assessment
- Confirmed mechanism of action documentation from DrugBank
- Direct evidence (trial or cohort data) evaluating stroke incidence as a primary endpoint for flecainide specifically, rather than as a secondary outcome of AF rhythm-control strategies
- Clarification of Taiwan regulatory pathway given current non-marketed status
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.