磺胺二甲嘧啶在健康和巴氏杆菌病兔单次和多次静注的动力学

SINGLE-AND MULTIPLE-DOSE PHARMACOKINETICS OF IUTRAVENOUS ADMINISTERED SULFADIMIDINE IN HEALTHY RABBITS AND RABBITS INFECTED EXPERIMENTALLY WITH PASTEURELLA MULTOCIDA

用新西兰白兔１９只研究多次静注和多杀性巴氏杆菌病（ＰＭ）对磺胺二甲嘧啶（ＳＭ＿２）动力学的影响，血中ＳＭ＿２用分光光度法测定，药时数据用矩量法和预测方程法分析。结果显示，无论是在健康还是在发病兔，ＳＭ＿２多次静注后分布容积增加，清除率（含乙酰化率）下降，ＰＭ对ＳＭ２单次静注的动力学无显著影响，确使ＳＭ＿２多次静注的分布容积和药时曲线下面积增加，消除半衰期和平均滞留时间延长，这些结果说明不能将健康动物单次给药的动力学结果外推到多次给药和病态的情形。

There are more theoretical and practical significances of pharmacokinetics of adrug in patients with contagious diseases.Nineteen New Zealand White rabbits wereused to investigate effects of multiple-dosing and Pasteurella multocida (PM)on phar-macokinetics of sulfadimidine(SM2)in rabbits.The concentrations of SM2 in the pla-sma were determined with spectrophotometry.The concentration-time data were analysedwith moment theory and predicting equations.It was shown that muItiple-dosing inceasedthe apparent distribution volume and decreased the total clearance(including acetylationratio)in both healthy and infected rabbits.PM had no marked effects on pharmacoki-netics of single-dosing SM2,but it increased the distribution volume and the area underthe curve,and prolonged the elimination half-life and the mean residance time ofmultiple-dosing SM2.The results suggest that it is not allowed to extrapolate muItiple-dose pharmacokinetics in diseased animals from sillgle-dose or multiple-dose pharmaco-kinetics in healthy animals.