Flecainide acetate

Flecainide acetate
INN
Drug class
Routes of administration	Oral
Pregnancy category
Bioavailability	90%
Metabolism	Hepatic
Elimination half-life	20 hours
Excretion	Renal
Legal status
CAS Number	54143-55-4
PubChem	3353
DrugBank	DB01195
ChemSpider	3237
KEGG	D07935

Flecainide acetate is a class Ic antiarrhythmic agent used to prevent and treat a variety of cardiac arrhythmias. It is particularly effective in the management of supraventricular tachycardia and ventricular tachycardia.

Pharmacology

Flecainide works by blocking the sodium channels in the heart, which slows the conduction of electrical impulses. This action stabilizes the cardiac cell membranes and reduces the excitability of the heart muscle, thereby preventing abnormal heart rhythms.

Mechanism of Action

Flecainide is a potent blocker of the fast inward sodium current (I_Na) in cardiac cells. By inhibiting sodium influx, it decreases the rate of rise of the action potential, prolongs the refractory period, and reduces automaticity in the heart. This results in a decrease in conduction velocity, particularly in the His-Purkinje system and the ventricles.

Pharmacokinetics

Flecainide is well absorbed from the gastrointestinal tract, with a bioavailability of approximately 90%. It is moderately bound to plasma proteins (about 40%) and is metabolized in the liver. The elimination half-life of flecainide is approximately 20 hours, and it is primarily excreted in the urine.

Clinical Uses

Flecainide is used in the treatment of various types of arrhythmias, including:

• Atrial fibrillation
• Atrial flutter
• Paroxysmal supraventricular tachycardia (PSVT)
• Ventricular tachycardia

It is particularly useful in patients with structurally normal hearts and is often used in "pill-in-the-pocket" strategies for atrial fibrillation.

Adverse Effects

Common side effects of flecainide include:

• Dizziness
• Visual disturbances
• Dyspnea
• Fatigue

Serious adverse effects can include:

• Proarrhythmia
• Heart failure
• Conduction disturbances

Contraindications

Flecainide is contraindicated in patients with:

• Heart failure
• Myocardial infarction
• Significant left ventricular dysfunction

Drug Interactions

Flecainide can interact with other medications, including:

• Beta blockers
• Calcium channel blockers
• Digoxin

These interactions can potentiate the effects of flecainide and increase the risk of adverse effects.

Monitoring

Patients on flecainide should be monitored for:

• ECG changes
• Signs of heart failure
• Plasma drug levels, if necessary

Conclusion

Flecainide acetate is a valuable medication in the management of certain cardiac arrhythmias. Its use requires careful patient selection and monitoring due to the potential for serious side effects and drug interactions.

List of antiarrhythmic agents:

• Amiodarone
• Disopyramide
• Dofetilide
• Dronedarone
• Flecainide
• Ivabradine
• Mexiletine
• Procainamide
• Propafenone
• Quinidine