title: [Study on the pharmacokinetic profile of telbivudine].
abstract: OBJECTIVE
  To evaluate the pharmacokinetic profile of telbivudine in healthy Chinese subjects after oral administration of single and multiple doses.
  
  
  METHODS
  Forty-two healthy adult male and female subjects 18-40 years of age were randomized into four telbivudine dosing groups of 200 mg, 400 mg, 600 mg and 800 mg. Subjects in the 600 mg group received both a single dose and once daily multiple doses for 8 consecutive days. Telbivudine concentrations in plasma and urine samples collected at different time points before and after the drug administration were measured using HPLC-MS/MS. Pharmacokinetic parameters were calculated by using the non-compartmental approach.
  
  
  RESULTS
  After a single dose of 200 mg, 400 mg, 600 mg and 800 mg, tmax (median) were 2.50, 2.00, 2.00 and 2.50 hours respectively; t1/2 were (43.3 +/- 15.2) h, (49.1 +/- 14.4) h, (39.4 +/- 12.1) h and (46.7 +/- 20.8) h respectively; Cmax were (1,753.2 +/- 389.0) ng/ml, (2,586.7 +/- 871.4) ng/ml, (3,703.6 +/- 1,219.0) ng/ml and (3454.6 +/- 953.9) ng/ml respectively; AUC(0-infinity) were (12,843.2 +/- 2,925.6) ng.h(-1).ml(-1), (22,948.9 +/- 5,721.0) ng.h(-1)/ml(-1), (26,440.5 +/- 8,938.1) ng.h(-1).ml(-1) and (28, 820.9 +/- 7 912.9) ng.h(-1).ml(-1) respectively, and CL(R) (600 mg) was (6,545.6 +/- 1 504.4) ml/h. The AUCss from multiple doses was (1,088.5 +/- 299.8) ng/ml; Cmax and AUC accumulation ratio were 1.02 +/- 0.21 and 1.23 +/- 0.26 respectively, which implicated moderated accumulation.
  
  
  CONCLUSIONS
  Pharmacokinetic parameters of telbivudine in Chinese healthy subjects were determined.
authors.affiliation: Center of Clinical Pharmacology, Peking Union Medical College Hospital, Beijing 100730, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Jiang
authors.forename: Pei
authors.initials: P
authors.lastname: Hu
authors.forename: Hong-yun
authors.initials: HY
authors.lastname: Wang
authors.forename: Kai
authors.initials: K
authors.lastname: Shen
authors.forename: Nathaniel A
authors.initials: NA
authors.lastname: Brown
authors.forename: Xiao-jian
authors.initials: XJ
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D000328:Adult; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D009705:Nucleosides / Q000493:pharmacokinetics*; D011744:Pyrimidinones / Q000493:pharmacokinetics*; D000077712:Telbivudine; D013936:Thymidine / Q000031:analogs & derivatives; D055815:Young Adult
chemical_list: D009705:Nucleosides; D011744:Pyrimidinones; D000077712:Telbivudine; D013936:Thymidine