title: Antipsychotic polypharmacy in a regional health service: a population-based study.
abstract: BACKGROUND
  To analyse the extent and profile of outpatient regular dispensation of antipsychotics, both in combination and monotherapy, in the Barcelona Health Region (Spain), focusing on the use of clozapine and long-acting injections (LAI).
  
  
  METHODS
  Antipsychotic drugs dispensed for people older than 18 and processed by the Catalan Health Service during 2007 were retrospectively reviewed. First and second generation antipsychotic drugs (FGA and SGA) from the Anatomical Therapeutic Chemical classification (ATC) code N05A (except lithium) were included. A patient selection algorithm was designed to identify prescriptions regularly dispensed. Variables included were age, gender, antipsychotic type, route of administration and number of packages dispensed.
  
  
  RESULTS
  A total of 117,811 patients were given any antipsychotic, of whom 71,004 regularly received such drugs. Among the latter, 9,855 (13.9%) corresponded to an antipsychotic combination, 47,386 (66.7%) to monotherapy and 13,763 (19.4%) to unspecified combinations. Of the patients given antipsychotics in association, 58% were men. Olanzapine (37.1%) and oral risperidone (36.4%) were the most common dispensations. Analysis of the patients dispensed two antipsychotics (57.8%) revealed 198 different combinations, the most frequent being the association of FGA and SGA (62.0%). Clozapine was dispensed to 2.3% of patients. Of those who were receiving antipsychotics in combination, 6.6% were given clozapine, being clozapine plus amisulpride the most frequent association (22.8%). A total of 3.800 patients (5.4%) were given LAI antipsychotics, and 2.662 of these (70.1%) were in combination. Risperidone was the most widely used LAI.
  
  
  CONCLUSIONS
  The scant evidence available regarding the efficacy of combining different antipsychotics contrasts with the high number and variety of combinations prescribed to outpatients, as well as with the limited use of clozapine.
authors.affiliation: Schizophrenia Clinic Program, Department of Psychiatry, Neuroscience Institute, Hospital Clinic de Barcelona, Barcelona, Spain. bernardo@clinic.ub.es
authors.forename: Miguel
authors.initials: M
authors.lastname: Bernardo
authors.forename: Anna
authors.initials: A
authors.lastname: Coma
authors.forename: Cristina
authors.initials: C
authors.lastname: Ibáñez
authors.forename: Corinne
authors.initials: C
authors.lastname: Zara
authors.forename: Josep Maria
authors.initials: JM
authors.lastname: Bari
authors.forename: Antoni
authors.initials: A
authors.lastname: Serrano-Blanco
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019338:Polypharmacy; D011618:Psychotic Disorders / Q000188:drug therapy*; D012189:Retrospective Studies; D013030:Spain
chemical_list: D014150:Antipsychotic Agents