Pharmacokinetic analysis of enterohepatic circulation of piroxicam in rabbits
Zhou, H.W.; Shen, J.Q.; Lu, M.; Liang, W.Q.; Lin, W.; Zhao, W.H.
Zhongguo Yao Li Xue Bao 13(2): 180-182
1992
ISSN/ISBN: 0253-9756 PMID: 1598837 Document Number: 399625
The concentration (c) - time (t) curves of piroxicam showed double peaks following iv 10 mg dose to 4 rabbits. A new mathematical model of enterohepatic circulation was proposed to explain this double-peak phenomenon and showed good agreement with data. This model provides not only the common pharmacokinetic parameters: T1/2 = 1.12 .+-. 0.32 h, V1 =0.64 .+-. 0.12 L, AUC = 34.7 .+-. 7.8 .mu.g .cntdot. h-1 .cntdot. ml-1, but also the parameters of enterohepatic circulations of piroxicam: the cycling amount of drug Db = 3.9 .+-. 1.4 mg, reasorption fraction Fb = 0.50 .+-. 0.04, reabsorption rate constant Ka = 2.55 .+-. 0.50 h-1. It is indicated in this study that enterohepatic circulation results in a 20% average increased of the effective among of piroxicam.