绝对生物利用度计算方法的讨论  

A discussion on the calculation of absolute bioavailability

作　　者：王放[1] 曹永孝[1] 狄佳[1] 

机构地区：[1]西安交通大学医学院,陕西西安710061

出　　处：《医学争鸣》2014年第2期51-53,共3页Negative

基　　金：2013年西安交通大学本科生科研训练和实践创新基金(2013275);2013年西安交通大学本科教学改革专题研究项目(27)

摘　　要：绝对生物利用度是药物吸收进入体循环的程度及速度,以血管外给药的血药浓度曲线下面积(AUC)占静脉注射血药浓度AUC的比值计算而得。然而静脉注射后的血药浓度在快速下降的分布相时,体内的药物分布并不平衡,因而血药浓度并不能反映体内的药物量。将分布相的各时间点代入消除相的血药浓度-时间关系公式,计算分布相各时间点的血药浓度才是分布平衡时的血药浓度。在中国知网以关键词"绝对生物利用度"检索1995年以来的文献,重新计算,发现静脉注射的药物浓度-时间AUC是实际的(1.31±0.22)倍,绝对生物利用度是实际的(79±10)%。这种低估绝对生物利用度的现象应予纠正。The absolute bioavailability is defined as the extent and speed when drug is absorbed into the systemic circulation after extravascular administration. It is calculated as the ratio between the area under the curve （AUC） of blood concentration after extravascular administration and the AUC of blood concentration after intravenous injection. However, drug distribution in the body doesn＇t reach equilibrium when the blood concentration is in the rapid decline at the distribution phase after intravascular administration. So at this moment, the blood concentration could not reflect the total amount of drug in the body. According to blood drug concentration-time relationship at the elimination phase, the blood drug concentration is calculated at each time point at the distribution phase, which represents the concentration of the drug in the body. The literatures since 1995 have been retrieved by the keyword ＂absolute bioavailability＂ at Chinese National Knowledge Infrastructure. As a result of recalculation, the intravenous AUC is 1.31±0.22 times larger than the actual one while the absolute bioavailability is （79±10）% of the actual one. Therefore, the underestimation of the absolute bioavailability should be paid attention to and corrected.

关 键 词：绝对生物利用度 血药浓度 分布平衡 曲线下面积 

分 类 号：R911[医药卫生—药学] R96