磺胺-5-甲氧嘧啶(SMD)在马体内的代谢动力学

本文研究了磺胺-5-甲氧嘧啶(SMD)在正常马体内的分布与消除动力学.单剂量快速静脉注射SMD 50mg/kg,药物动力学符合二项指数数学式:Cp=Ae~(-αt)+Be~(-βt).药物在马体内的分布半衰期(t(1/2)α)为0.13±0.09小时,消除半衰期(t(1/2)β)为5.76±1.22小时,表观分布容积(Vd)为4.91±0.46(100mg/kg).曲线下面积(AUC)为84.37±12.73(mg·h/100ml),中央室分布容积(Vc)为1.79±0.72(100ml/kg),清除率(Cl_B)为0.6030±0.0909(100ml/kg).本文还计算了多剂给药参数.给药后12小时的最高,平均与最低稳态浓度分别为21.52mg%,7.03mg%与2.81mg%,负荷剂量(D~*)为65.50mg/kg,蓄积因子(R)为1.31.本研究确定多剂量给药间隔时间为10小时.

PHARMACOKINETICS OF SULFAMETHOXYDIAZINUM (SMD) IN HORSES

The distribution and elimination kinetics of SMD was studied in normal horses. SMD was injected as a single intravenous bolus at the dose of 50mg/ kg and the kinetics of the drug were described in terms of the biexponential expression: Cp=Ae~(-αt)+ Be~(-βt). The distribution half-times ( t(1/2)α) of the drug was 0.13±0.09h.,the elimination half-times ( t(1/2)β )of the drug was 5.76±1.22h.,the apparent volume of distribution (V_d) was 4.91±0.46(100mg/kg), the area under curve (AUC) was 84.37±12.73 (mg.h/100ml), the volume of the central compartment (Vc) was 1.79±0.72 (100ml/kg) , the total body clearance (Cl_B)was 0.6030±0.0909 (100ml/kg) in the horses. The parameters of multiple dosage regimen were calculated. The maximum,average, and minimum plateau plasma concentration at posttreatment hour 12 were 21.52mg%, 7.03mg% and 2.81mg%, respectively; the loading dose (D*)was 65.50mg/kg, the accumulation factor (R) was 1.31. This investigation indicated, that the dosage intervals for multiple doses of the drug were 10 hour.