Flecainid HEXAL

Flecainide Acetate

Method of action: Antiarrhythmic, Cardiac Therapy, Group Ic

Treatment option: Arrhythmia, Left Ventricular Dysfunction, Ventricular Tachycardia, Premature Ventricular Contractions, Paroxysmal Atrial Fibrillation, Wolff-Parkinson-White Syndrome, Tachycardia, AF

Medically reviewed

Marina Burgos

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Flecainid HEXAL

Property	Description
Active ingredient	Flecainide Acetate
Form	Tablet (Oral route)
Pharmacological class	Antiarrhythmic Agent (Class IC)
General purpose	Management of abnormal heart rhythms
Origin	Synthetic agent
Manufacturer	HEXAL AG (Part of Sandoz Group)
Status	Prescription-only (Rx-only)

What Type of Medicine is Flecainid HEXAL and its Medical Classification?

Flecainid HEXAL is a specialized, prescription-only synthetic agent whose active ingredient is the chemical substance Flecainide Acetate. Manufactured by the generic pharmaceutical company HEXAL AG, the product provides a therapeutically established form of the antiarrhythmic agent. It is typically administered via the oral route in the pharmaceutical preparation of a tablet.

The drug is formally classified as a Class IC antiarrhythmic agent within the authoritative Vaughan Williams system. This designation is supported by pharmacological studies that confirm its highly specific mechanism. This substance is a chemically derived, synthetic agent, ensuring its composition and pharmacological properties are consistently standardized.

How Does Flecainide Affect the Heart's Rhythm?

The primary purpose of Flecainide is to help the heart maintain a regular and steady rhythm when it is prone to beating too quickly or erratically. The medicine achieves this through a specific membrane stabilizing effect on cardiac cells.

Flecainide Acetate functions as a selective sodium channel blocker. By precisely moderating the flow of electrical current carried by sodium ions into the heart cells, the drug effectively dampens the rapid, disorganized electrical impulses that trigger and sustain abnormal rhythms. Its use is clinically recognized for the prevention and management of various tachyarrhythmias, promoting a more consistent and efficient cardiac function.

What side effects are possible with Flecainid HEXAL?

Possible side effects and safety information

Flecainide Acetate's safety profile, as documented in official regulatory labeling, is primarily defined by its effects on the cardiovascular and nervous systems, ranging from common observations to serious, infrequent adverse reactions.

Officially Documented Adverse Reactions by Frequency

Regulatory documents classify side effects to establish the likely rate of occurrence:

Very Common (Affecting ge 1 in 10 patients): Dizziness and various vision disorders, such as blurred vision or seeing double (diplopia). These effects often appear at the beginning of treatment or during dose adjustments.
Common (Affecting ge 1 in 100 to <1 in 10 patients): Fatigue, weakness (asthenia), headache, tremor, shortness of breath (dyspnea), nausea, constipation, abdominal pain, diarrhea, and dyspepsia.

Serious Adverse Reactions and Safety Constraints

Regulatory agencies explicitly document the potential for severe adverse reactions, which include proarrhythmia, meaning the medicine can cause new or worsen existing abnormal heart rhythms, and the exacerbation of pre-existing heart failure.

The medicine is strictly contraindicated and should not be used in individuals with underlying structural heart disease (e.g., following a heart attack with asymptomatic ventricular ectopics) due to an increased risk of serious adverse cardiovascular events. It is also prohibited for use in patients with established second- or third-degree atrioventricular block or sick sinus syndrome unless a functioning pacemaker is present.

Population-Specific Considerations

Special safety considerations are listed for certain populations. Patients with known hepatic or renal impairment require particularly careful monitoring, as the clearance of Flecainide Acetate from the body may be significantly reduced, increasing the risk of adverse reactions. Similarly, older adults may require cautious monitoring due to a potentially reduced clearance rate.

Overdose and Emergency Response

Overdose and When to Seek Help

The official regulatory profile for Flecainide Acetate defines overdose as a critical medical emergency due to the high potential for severe cardiotoxicity. Documented overdose manifestations involve both cardiovascular and central nervous system (CNS) effects.

Cardiovascular signs listed in official labeling include slow heart rate (bradycardia), irregular rhythms, and critical electrocardiographic abnormalities, such as widening of the QRS complex. Overdose can lead to severe or life-threatening outcomes, including ventricular fibrillation, asystole, and the risk of sudden death. CNS manifestations include the possibility of seizures and loss of consciousness.

Government authorities mandate that individuals seek immediate medical attention for any suspected overdose. Emergency services or a Poison Control Centre must be contacted immediately if symptoms such as collapse, difficulty breathing, unresponsiveness, or a seizure are observed.

Management is focused on aggressive symptomatic and supportive treatment, as regulatory documents explicitly state that no specific antidote is known. Specific supportive measures, such as the use of high-dose hypertonic sodium bicarbonate, are documented for managing severe cardiac conduction blockade. Furthermore, regulatory documents note that patients with pre-existing renal or hepatic impairment may face increased risk and severity of overdose effects due to altered drug clearance.

Therapeutic Uses of Flecainid HEXAL

What Flecainid HEXAL treats: main uses and benefits

Flecainid HEXAL contains the active substance flecainide acetate, which belongs to a group of medicines known as class Ic anti-arrhythmics. It is used to manage certain types of irregular heartbeats (arrhythmias) by slowing down nerve impulses in the heart and stabilizing the electrical signals that coordinate the heartbeat.

Main Uses

This medication is primarily prescribed for the treatment of specific serious heart rhythm disorders. These include:

Supraventricular Arrhythmias: Conditions where the heart beats too fast or irregularly due to electrical issues originating in the upper chambers of the heart. This includes paroxysmal atrial fibrillation and paroxysmal atrial flutter in patients with disabling symptoms.
Ventricular Arrhythmias: Treatment of serious symptomatic ventricular tachycardias (rapid heartbeats originating in the lower chambers) that have been judged to be life-threatening by a physician.

Benefits and Mechanism of Action

The primary benefit of Flecainid HEXAL is its ability to restore and maintain a normal heart rhythm. It works by blocking sodium channels in the heart muscle cells, which prolongs the time it takes for the heart to reset between beats. This helps to:

Prevent the onset of sudden, rapid heart rates.
Reduce the frequency of episodes of palpitations and irregular heartbeats.
Stabilize the conduction of electrical impulses throughout the heart tissue.

By regulating the electrical activity of the heart, the medication aims to improve the overall efficiency of blood circulation and alleviate the physical discomfort associated with rhythm disturbances.

Regulatory References

Flecainide Acetate Tablets, USP - DailyMed

Eligibility and Restrictions for Use

Flecainid HEXAL is used for treating specific serious heart rhythm disorders, primarily in patients without structural heart disease.

Who Can Use Flecainid HEXAL (Indications)

Flecainid is typically prescribed for the treatment of certain supraventricular tachycardias (fast heart rhythms originating above the ventricles) and life-threatening ventricular arrhythmias, especially in individuals with otherwise healthy hearts.

Who Cannot Use Flecainid HEXAL (Contraindications)

Due to the risk of serious side effects, including the potential to worsen heart rhythm problems, Flecainid HEXAL is generally contraindicated (should not be used) in patients with the following conditions:

Structural Heart Disease: This includes individuals with a history of myocardial infarction (heart attack), or conditions that cause reduced pumping function of the heart (such as moderate to severe congestive heart failure) or left ventricular dysfunction.
Specific Heart Conduction Problems: These include second- or third-degree atrioventricular (AV) block, right bundle-branch block when combined with a left hemiblock (bifascicular block), or sick sinus syndrome, unless a functioning artificial pacemaker is present.
Cardiogenic Shock (a life-threatening form of heart failure).
Hypersensitivity or allergy to flecainide or any other ingredients in the medication.

Caution and dose adjustment are also necessary for patients with severe kidney or liver impairment, or uncorrected electrolyte imbalances (such as low potassium or magnesium), as these can increase the risk of adverse effects.

What should I know about interactions with other medicines?

Flecainid HEXAL Interactions with other medicines and products

The interaction profile of Flecainide Acetate is characterized by both pharmacokinetic and pharmacodynamic patterns, as documented in official government labeling. These interactions establish specific constraints for co-administration.

Contraindicated and Restricted Combinations

Substance Category	Official Restriction/Outcome
Class I Antiarrhythmics	Co-administration is formally contraindicated due to additive arrhythmogenic risk.
Verapamil, Disopyramide	Not recommended for concurrent use due to potential additive negative effects on heart function.

Interactions Altering Plasma Exposure

Flecainide undergoes metabolism, primarily involving the CYP2D6 enzyme system. Agents that inhibit or induce this system can alter the medicine’s concentration in the body.

Interacting Medicine	Official Pharmacokinetic Outcome
Amiodarone	Significantly increases plasma flecainide levels (often two-fold or more) due to metabolic inhibition.
Cimetidine	Increases plasma flecainide levels by approximately 30% through reduced clearance.
Enzyme Inducers (e.g., Phenytoin)	Increases the rate of flecainide elimination by 30%, which can reduce systemic exposure.

Mechanism of Action

Targeted Modulation of Cardiac Electrical Activity

Flecainid HEXAL functions as an inhibitor of voltage-gated sodium channels (Na^+ channels) located within the specialized electrical conduction system and muscle cells of the heart. This interaction represents the core mechanistic domain, where the drug physically binds to and blocks the channel, impeding the rapid influx of sodium ions into the cell. This specific action primarily targets and delays Phase 0 (depolarization) of the cardiac action potential .

By restricting the flow of sodium ions, the drug significantly slows the speed at which electrical impulses are transmitted throughout the heart tissue, particularly in the His-Purkinje system. This modification to the electrical pathway prolongs the effective refractory period, which dictates the required recovery time before a heart cell can undergo re-excitation. The resultant physiological consequence is a reduction in the cellular capacity for generating early or repetitive electrical impulses, fostering a greater uniformity in electrical signal transmission and modulating cardiac electrical activity.

Dosage and Administration Information

How to Use Flecainid HEXAL: Official Administration Guidelines

Flecainid HEXAL is administered orally as a tablet and is generally taken every 12 hours (twice daily) to maintain a consistent therapeutic level. It is permissible to take the dose with or without food. To minimize fluctuations in drug concentration, patients should adhere to a strict dosing schedule, ideally taking the medication at the same times each morning and evening.

Official Dosing and Administration Rules

Patient Group	Initial Dose	Maximum Daily Dose	Special Conditions
Adults (most conditions)	50 mg twice daily	300 mg (or 400 mg for sustained VT)	Doses may be increased in increments of 50 mg twice daily at intervals of at least four days to assess efficacy and safety.
Elderly	50 mg twice daily	300 mg	Dosage increase must be managed with caution and close monitoring.
Severe Renal Impairment	50 mg twice daily	100 mg	Close monitoring of plasma levels is essential; use with extreme caution.

Procedural Instructions

Initial Therapy: Treatment for sustained ventricular arrhythmias is often initiated in a hospital setting with continuous cardiac monitoring.
Missed Dose: If a dose is missed, it should be taken as soon as remembered. However, if it is almost time for the next scheduled dose, the missed dose should be skipped, and the patient should return to the regular dosing schedule. Do not take a double dose to compensate.
Pediatric Use: The routine use of flecainide in children under 12 years of age is not recommended. If used for serious conditions, the dose is based on body size and divided into two or three equal doses per day. Dosing for infants may require adjustment based on changes in milk intake.

This medication must be used exactly as prescribed by a healthcare professional under close supervision to manage the underlying condition effectively.

Recent Clinical Evidence

Research evidence / Overview of studies for Flecainid HEXAL

The research base for Flecainid Acetate includes formal studies, such as Randomized Controlled Trials (RCTs) and comprehensive Meta-analyses, which are reviewed by regulatory bodies. The evidence explores how the medicine may affect heart rhythm patterns and focuses on specific, authorized uses. This overview describes the research structure and must not be used as clinical guidance or individual advice.

Evidence for Use in Managing Supraventricular Arrhythmias (SVA)

Research has explored the use of Flecainide in patients with conditions characterized by fluctuating or episodic manifestations, like Paroxysmal Atrial Fibrillation/Flutter and Paroxysmal Supraventricular Tachycardia (PSVT). Studies explored rhythm control in patients experiencing frequent episodes. Core RCTs evaluated the maintenance of normal heart rhythm (Sinus Rhythm) over time and the ability for pharmacological cardioversion. Researchers also examined outcomes related to patient-reported experiences and Quality of Life (QoL). Findings described patterns related to conversion rates, but also noted the potential for the drug to organize Atrial Fibrillation into a fast Atrial Flutter.

Evidence for Use in Documented Ventricular Arrhythmias (VA)

The research landscape for Flecainide was studied for use in patients with serious life-threatening ventricular rhythms. This evidence is based on RCTs, including the pivotal Cardiac Arrhythmia Suppression Trial (CAST), which tracked overall mortality and cardiac arrest. Research highlights measurements showing data describing patterns related to the monitored rate of ventricular events. However, CAST reported an unexpected pattern of increased mortality when the drug was observed in post-heart attack patients with asymptomatic ventricular arrhythmias. This finding fundamentally shaped the patient populations explored, resulting in significant restrictions.

What Research Gaps and Uncertainties Remain

Intermediate-term research was studied for rhythm maintenance over several months, but long-term outcomes are not well characterized beyond follow-up durations of less than a year. The strict research limitations imposed by the adverse finding in the CAST study mean that evidence is limited for the majority of patients with underlying heart conditions. Furthermore, data for certain groups remain insufficient, including pediatric or elderly populations.

Key Studies & References

Frequently Asked Questions (FAQ)

Common questions about Flecainid HEXAL (FAQ)

Q: What is Flecainid HEXAL used for?

A: Flecainid HEXAL is a medication that belongs to a class of drugs known as antiarrhythmics. It is typically indicated for managing certain types of abnormal heart rhythms (arrhythmias), such as paroxysmal atrial fibrillation/flutter or paroxysmal supraventricular tachycardia, in patients where the arrhythmia is symptomatic and disabling.

Q: How does Flecainid HEXAL relate to heart rhythm?

A: The medication is designed to affect the electrical signals in the heart muscle. By influencing the movement of certain ions in the heart cells, it is thought to help restore and maintain a more regular heart rhythm in affected individuals.

Q: What kind of evidence supports the use of this medication?

A: Clinical studies have investigated the use of flecainide for maintaining sinus rhythm in individuals with certain symptomatic supraventricular tachycardias and atrial fibrillation. The collected evidence is used by regulatory bodies to determine the drug's approved indications.

Q: Are there known potential side effects?

A: Like all medications, Flecainid HEXAL may be associated with side effects. Common observed effects can include dizziness, vision disturbances, or tremor. More serious potential effects on the heart rhythm have also been reported in clinical contexts, which is why the drug is generally prescribed under careful monitoring.

Q: Is Flecainid HEXAL the only treatment option for arrhythmias?

A: Flecainid HEXAL is one of several types of antiarrhythmic medications and treatment strategies available. The choice of therapy depends on the specific type of arrhythmia, the patient's overall health status, and other concurrent medical conditions, and is determined by a healthcare provider.

How should Flecainid HEXAL be stored and disposed of?

How to Store and Dispose of Flecainid HEXAL

Flecainide acetate tablets must be stored according to official regulatory requirements to ensure product integrity and stability.

Storage Condition	Requirement
Temperature & Environment	Store in a closed container at room temperature; keep away from heat, moisture, and direct light. Do not freeze.
Child Safety	Keep out of the reach and sight of children

The medicine is generally required to be kept in its original, closed container. Storage conditions, such as maintaining protection from light and moisture, are mandatory to preserve the product until the expiry date.

For disposal, unused or expired flecainide should not be thrown into the household trash or flushed down the toilet, unless explicitly authorized by the regulator. Patients are officially instructed to ask their healthcare professional or pharmacist for guidance on the proper disposal of the product.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.