title: Comparison of the effects of levofloxacin on QT/QTc interval assessed in both healthy Japanese and Caucasian subjects (pages.
abstract: OBJECTIVE
  There is no consensus as to what extent the results of thorough QT interval/corrected QT interval (QT/QTc) studies need to be bridged.
  
  
  METHODS
  The results of two studies using levofloxacin in Japanese and Caucasian subjects were compared in a post hoc analysis to investigate the similarity of dose–effect responses.
  
  
  RESULTS
  Concentration–response analysis based on the change of QT interval corrected using Fridericia's formula (QTcF) from time-matched placebo was planned and performed in the combined data sets. At the geometric maximum mean concentration for the two doses in the Caucasian study, a predicted effect on QTcF comparable to the effects observed was found. For the Japanese study, the predicted effect was lower, but the difference was not statistically significant.
  
  
  CONCLUSIONS
  No statistically significant differences in QTc-prolonging effect between Japanese and Caucasian subjects were observed following levofloxacin dosing. However, a trend suggests that Caucasian subjects may be more sensitive. Age and sex did not have an impact.
authors.affiliation: Department of Pharmacology, School of Medicine, Faculty of Medicine, Toho University,Omori-NishiOta-ku, Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sugiyama
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Satomi
authors.initials: S
authors.lastname: Nishimura
authors.forename: Satomi
authors.initials: S
authors.lastname: Adachi-Akahane
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kumagai
authors.forename: Juleen
authors.initials: J
authors.lastname: Gayed
authors.forename: Asif
authors.initials: A
authors.lastname: Naseem
authors.forename: Georg
authors.initials: G
authors.lastname: Ferber
authors.forename: Jorg
authors.initials: J
authors.lastname: Taubel
authors.forename: John
authors.initials: J
authors.lastname: Camm
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D019540:Area Under Curve; D044466:Asian People; D002986:Clinical Trials as Topic; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography / Q000187:drug effects*; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D064704:Levofloxacin; D008297:Male; D008875:Middle Aged; D015242:Ofloxacin / Q000008:administration & dosage*; D012044:Regression Analysis; D012189:Retrospective Studies; D044465:White People; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D064704:Levofloxacin; D015242:Ofloxacin