title: Amitriptyline: linear or nonlinear kinetics in every day practice?
abstract: The linearity of the (AMT) kinetics of amitriptyline has been tested in 135 depressed dosed twice daily by measuring plasma. Their (AMT) and nortriptyline (NT) levels under steady-state conditions. The AMT concentration/dose ratios at low and high dosages were not significantly different and there was a linear relationship between the dose ratios and the concentration ratios. No change in the metabolic ratio (AMT/NT) was observed between the two dosages. Although the results are consistent with linear AMT kinetics, there may have been nonlinear kinetics in some patients as the ratio between the concentration/dose ratios in them at low and high dosages was greater than one. Those patients were characterized by a low concentration/dose ratio at low dosage. No clinical adverse effect appeared in the study.
authors.affiliation: Laboratoire de Pharmacologie Clinique, CHU of Besançon, France.
authors.forename: S
authors.initials: S
authors.lastname: Vandel
authors.forename: G
authors.initials: G
authors.lastname: Bertschy
authors.forename: B
authors.initials: B
authors.lastname: Vandel
authors.forename: G
authors.initials: G
authors.lastname: Allers
authors.forename: R
authors.initials: R
authors.lastname: Volmat
mesh_terms: D000639:Amitriptyline / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D001711:Biotransformation; D003863:Depression / Q000188:drug therapy*; D006801:Humans; D016014:Linear Models; D009661:Nortriptyline / Q000097:blood*
chemical_list: D000639:Amitriptyline; D009661:Nortriptyline