| Abstract: | The pharmacokinetics and pharmacodynamics of propafenone were investigated by a high performance liquid chromatography method.The detection limit of propafenone was 50 ng/ml in plasma. 11 patients with paroxysmal supraventricular tachycardia(PSVT)(atrioventricular node reentrant tachycardia,AVNRT n=6;atrioven tricular reentrant tachycardia,AVRT n=5)received intravenous injection of different doses of propafenone,a two compartment open model was used in all of them. The main phamacokinetics parameters:T(1/2) α was 0.05 h,T(1/2) βwas 2.99 h,Vc was 0.048 L/kg. The effective concentration for ending PSVT was 1 032.6±624.1ng/ml.There was no significant diffenence in effective concentration,effective dosage and ending time between AVRT group and AVNRT group(P> 0.05).15 patients with ventricular arrhythmia were studied after receiving three increasing doses from 300 mg/d,450 mg/d to 600 mg/d.The process of pharmacokinetics was described by a open one compartment model in steady state. The main pharmacokinetics parameters of those patients who took propafenone 450 mg/d orally were:T1/2α was 0.33 h,T1/2 βwas 6.89 h,TPk was 1.95 h,Cst was 243.4ng/ml.93%of patients were extensive metabolism. The effect of propafenone 450 mg daily in 13 patients with premature ventricular beats was 69.2%,the effective plasma concentration was 297.7±264.6 ng/ml.The difference of plasma concentration was very significant among the individual with same dose and at the same time. It must be emphasized that the clinical appplication of propafenone should be individually and the therapeutic or proarrhythmic effect could not be predicted according to the plasma concentration of propafenone. |
