Flecainide: evidence of non-linear kinetics

Area of Science:

• Clinical Pharmacology
• Cardiac Electrophysiology

Background:

• Flecainide is an antiarrhythmic drug used for ventricular arrhythmias.
• Understanding flecainide pharmacokinetics is crucial for safe and effective treatment.

Purpose of the Study:

• To investigate the pharmacokinetics of flecainide in patients with ventricular arrhythmias.
• To compare flecainide kinetics after single versus chronic administration.

Main Methods:

• Pharmacokinetic analysis in 12 patients with ventricular arrhythmias.
• Single and chronic dose administration of flecainide.
• Measurement of plasma flecainide levels, half-life, and AUC.

Main Results:

• Flecainide half-life and AUC significantly increased during chronic treatment.
• Observed non-linear kinetics, even in patients with normal organ function.
• Increases in plasma flecainide levels were unpredictable.

Conclusions:

• Flecainide exhibits non-linear pharmacokinetics during chronic treatment.
• Plasma flecainide levels can increase unpredictably, necessitating close monitoring.
• Therapeutic drug monitoring is recommended for flecainide therapy.