title: The evolution of antipsychotic switch and polypharmacy in natural practice--a longitudinal perspective.
abstract: OBJECTIVE
  Most patients with schizophrenia first start with a single antipsychotic, and yet most finally end up 'switching' or using 'polypharmacy'. The objective of this study was to examine the evolution of antipsychotic switch and polypharmacy in the real-world from a longitudinal perspective.
  
  
  METHODS
  A systematic review of longitudinal antipsychotic prescriptions in 300 patients with schizophrenia (ICD-10) for up to 2 years after their first visit to one of the 4 participating psychiatric clinics in Tokyo, Japan between January, 2007 and June, 2008, was conducted. Reasons for prescription change were also examined. The evolution of switching and polypharmacy was studied, and prescribed doses were compared to suggested dose ranges by the Texas Medication Algorithm Project (TMAP).
  
  
  RESULTS
  208 patients started their antipsychotic treatment with monotherapy. 34.1% of the patients gave up monotherapy with an initial antipsychotic to move to antipsychotic switch (27.4%) and/or polypharmacy (17.8%) within 2 years. The main reason for antipsychotic switch was 'ineffectiveness'; interestingly, this happened despite the fact that the monotherapy dose was below the recommended range in 47.4% of the antipsychotic switch. In a subgroup of 100 patients who started as antipsychotic-free, 2-year prevalence rates of switching and antipsychotic polypharmacy were 27.0% and 18.0%, respectively, and polypharmacy was resorted to after a median of 1 antipsychotic had been tried for 84 days (median).
  
  
  CONCLUSIONS
  These findings raise a concern that physicians may perform an antipsychotic switch without exploring the entire dose range and resort to antipsychotic polypharmacy without trying an adequate number of antipsychotics.
authors.affiliation: Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Chisa
authors.initials: C
authors.lastname: Tsutsumi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Uchida
authors.forename: Takefumi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Koichiro
authors.initials: K
authors.lastname: Watanabe
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Nakajima
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Kimura
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Tsutsumi
authors.forename: Koichi
authors.initials: K
authors.lastname: Ishii
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Imasaka
authors.forename: Shitij
authors.initials: S
authors.lastname: Kapur
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007564:Japan; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic / Q000379:methods; D019338:Polypharmacy; D012189:Retrospective Studies; D012559:Schizophrenia / Q000188:drug therapy*; D012565:Schizophrenic Psychology; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents