抄録
The present study was undertaken to elucidate the pharmacokinetics of procainamide (PA) in 4 Japanese who were found to be so-called fast acetylators. PAwas injected intravenously and the serum concentrations of PA and N-acteylprocainamide (NAPA) were determined, following which the pharmacokinetic parametersof PA were calculated. In this study, it was found that the elimination rateconstant (kμ) ranged from 0.22 to 0.43hr-1, the apparent volume of distribution (Vdarea) ranged from 1.80 to 3.57 1/kg, body clearance (Clb) ranged from 0.65 to 1.39l/kg/hr, and the area under the curve (AUC) ranged from 2.99 to 5.22 μg/hr/ml.Even after repeated oral administration to Japanese subjects, the serum concentration of PA did not reach the therapeutic range recommended by previousworkers, while on the other hand, a remarkable increase in serum concentrationof NAPA accompanied by the equilibrium state of serum PA concentration wasnoted. From the present results, it was suggested that the serum concentrations ofboth PA and NAPA should be taken into consideration in order to evaluate theantiarrhythmic effect after PA administration to Japanese subjects, most ofwhom are fast acetylators.
