title: Population pharmacokinetic modeling and simulation of huperzine A in elderly Chinese subjects.
abstract: OBJECTIVE
  Our preliminary results show that huperzine A, an acetylcholinesterase inhibitor used to treat Alzheimer's disease (AD) patients in China, exhibits different pharmacokinetic features in elderly and young healthy subjects. However, its pharmacokinetic data in elderly subjects remains unavailable to date. Thus, we developed a population pharmacokinetic (PPK) model of huperzine A in elderly Chinese people, and identified the covariate affecting its pharmacokinetics for optimal individual administration.
  
  
  METHODS
  A total of 341 serum huperzine A concentration records was obtained from 2 completed clinical trials (14 elderly healthy subjects in a phase I pharmacokinetic study; 35 elderly AD patients in a phase II study). Population pharmacokinetic analysis was performed using the non-linear mixed-effect modeling software Phoenix NLME1.1.1. The effects of age, gender, body weight, height, creatinine, endogenous creatinine clearance rate as well as drugs administered concomitantly were analyzed. Bootstrap and visual predictive checks were used simultaneously to validate the final population pharmacokinetics models.
  
  
  RESULTS
  The plasma concentration-time profile of huperzine A was best described by a one-compartment model with first-order absorption and elimination. Age was identified as the covariate having significant influence on huperzine A clearance. The final PPK model of huperzine A was: CL (L/h)=2.4649(*)(age/86)((-3.3856)), Ka=0.6750 h(-1), V (L)=104.216. The final PPK model was demonstrated to be suitable and effective by the bootstrap and visual predictive checks.
  
  
  CONCLUSIONS
  A PPK model of huperzine A in elderly Chinese subjects is established, which can be used to predict PPK parameters of huperzine A in the treatment of elderly AD patients.
authors.affiliation: Department of Clinical Pharmacology, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Sheng
authors.affiliation: Department of Geriatrics, Central Hospital of Shanghai Xuhui, Shanghai 200031, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Qu
authors.affiliation: Zhejiang Hospital, Hangzhou 310013, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yan
authors.affiliation: Central Laboratory, Central Hospital of Shanghai Xuhui, Shanghai 200031, China.
authors.forename: Gang-Yi
authors.initials: GY
authors.lastname: Liu
authors.affiliation: Department of Geriatrics, Central Hospital of Shanghai Xuhui, Shanghai 200031, China.
authors.forename: Wei-Liang
authors.initials: WL
authors.lastname: Wang
authors.affiliation: Central Laboratory, Central Hospital of Shanghai Xuhui, Shanghai 200031, China.
authors.forename: Yi-Jun
authors.initials: YJ
authors.lastname: Wang
authors.affiliation: Central Laboratory, Central Hospital of Shanghai Xuhui, Shanghai 200031, China.
authors.forename: Hong-Yi
authors.initials: HY
authors.lastname: Wang
authors.affiliation: Central Laboratory, Central Hospital of Shanghai Xuhui, Shanghai 200031, China.
authors.forename: Meng-Qi
authors.initials: MQ
authors.lastname: Zhang
authors.affiliation: Central Laboratory, Central Hospital of Shanghai Xuhui, Shanghai 200031, China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Lu
authors.affiliation: Central Laboratory, Central Hospital of Shanghai Xuhui, Shanghai 200031, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Central Laboratory, Central Hospital of Shanghai Xuhui, Shanghai 200031, China.
authors.forename: Jing-Yin
authors.initials: JY
authors.lastname: Jia
authors.affiliation: Central Laboratory, Central Hospital of Shanghai Xuhui, Shanghai 200031, China.
authors.forename: Chao-Ying
authors.initials: CY
authors.lastname: Hu
authors.affiliation: Department of Clinical Pharmacology, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
authors.forename: Xue-Ning
authors.initials: XN
authors.lastname: Li
authors.affiliation: Central Laboratory, Central Hospital of Shanghai Xuhui, Shanghai 200031, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Yu
authors.affiliation: Department of Clinical Pharmacology, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
authors.forename: Hong-Rong
authors.initials: HR
authors.lastname: Xu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood*; D000470:Alkaloids / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics*; D044466:Asian People; D001827:Body Height; D001835:Body Weight; D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D017711:Nonlinear Dynamics; D012717:Sesquiterpenes / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics*; D012727:Sex Characteristics
chemical_list: D000470:Alkaloids; D012717:Sesquiterpenes; C050426:huperzine A; D003404:Creatinine