title: Tricyclic antidepressants: is your patient taking them? Observations on adherence and unreported use using prescriber-reported medication lists and urine drug testing.
abstract: OBJECTIVE
  Tricyclic antidepressants (TCAs) are first-line treatment for neuropathic pain. Despite widespread use, many health care providers do not know which patients are currently taking TCAs. The objective of this retrospective data analysis was to determine adherence rates to amitriptyline, nortriptyline, or imipramine. The rate at which patients used TCAs (confirmed by presence of TCA in the urine) but did not inform their health care provider is also reported (non-informed prescriber rate). Finally, the effects of age, sex, and number of prescriptions on adherence and non-informed prescriber rates were assessed.
  
  
  METHODS
  Urinary excretion data were obtained from 55,296 patients with pain and were analyzed using liquid chromatography tandem mass spectrometry in a multiplex assay which included amitriptyline, nortriptyline, and imipramine.
  
  
  RESULTS
  The adherence rate was 66% (1,407/2,137); the rate of non-informed prescribers was 3% (1,547/55,296) among the general population, and 52% (1,547/2,954) when only TCA users were considered. While adherence was higher among older and female subjects, the number of other medications did not affect adherence rate.
  
  
  CONCLUSIONS
  This analysis reveals that many prescribers are not informed when patients start and stop using TCAs.
authors.affiliation: Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego (UC San Diego), La Jolla, California, USA.
authors.forename: Sophie J
authors.initials: SJ
authors.lastname: Bordson
authors.forename: Rabia S
authors.initials: RS
authors.lastname: Atayee
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Ma
authors.forename: Brookie M
authors.initials: BM
authors.lastname: Best
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000639:Amitriptyline / Q000652:urine*; D000929:Antidepressive Agents, Tricyclic / Q000627:therapeutic use* / Q000652:urine; D004347:Drug Interactions; D005260:Female; D006801:Humans; D007099:Imipramine / Q000652:urine*; D008297:Male; D008875:Middle Aged; D009661:Nortriptyline / Q000652:urine*; D010146:Pain / Q000188:drug therapy*; D012189:Retrospective Studies; D012737:Sex Factors; D055815:Young Adult
chemical_list: D000929:Antidepressive Agents, Tricyclic; D000639:Amitriptyline; D009661:Nortriptyline; D007099:Imipramine
keywords: Adherence; Chronic Pain; Tricyclic Antidepressants; Urine Drug Testing