The relationship between the plasma concentration of bepridil and its efficacy in the treatment of atrial fibrillation in Japanese patients.

Bepridil hydrochloride is used for treatment of atrial fibrillation (AF) in Japan. We investigated the relationship between plasma concentrations of bepridil just before dosing (Cbep) and its clinical efficacy in Japanese patients (n=36) with AF. Patients were treated orally with 100, 150 or 200 mg/d bepridil.

An LC method for quantifying bepridil in human plasma using 1-naphthol as the internal standard.

A modified method for the quantitative determination of bepridil hydrochloride in human plasma is described. This method is unrelated to chemical methods currently in use. The mobile phase is 50 mM phosphate buffer (pH3.