title: The risks and benefits of switching patients with schizophrenia or schizoaffective disorder from two to one antipsychotic medication: a randomized controlled trial.
abstract: BACKGROUND
  Despite little evidence to support its use and practice guidelines discouraging the practice, antipsychotic polypharmacy is widely prevalent in schizophrenia. This randomized controlled trial studied the effects of switching patients stable on two antipsychotic medications to one antipsychotic medication.
  
  
  METHODS
  104 adult outpatients with schizophrenia from 7 community mental health centers clinically stable on concurrent treatment with 2 antipsychotics were randomly assigned to stay on polypharmacy or to switch to antipsychotic monotherapy. Participants were followed for 1-year with assessments of symptoms and side effects occurring every 60days (7 total assessments). We examined differences in time trajectories in symptoms (PANSS, CGI) and side effects (EPS, metabolic, other) as a function of group assignment (switch vs. stay) and time, using intention-to-treat analysis.
  
  
  RESULTS
  Participants who switched to antipsychotic monotherapy experienced greater increases in symptoms than stay patients. These differences emerged in the second 6months of the trial. All-cause discontinuation rates over the 1-year trial were higher in the switch-to-monotherapy group than in the stay-on-polypharmacy group (42% vs. 13%; p<0.01). There were no differences in change over time in any of the side effect measures, except that stay patients experienced a greater decrease in Simpson Angus total scores than switch patients.
  
  
  CONCLUSIONS
  Clinicians should be cautious in switching patients with chronic schizophrenia who are stable on 2 antipsychotics to one antipsychotic. Given the challenges in discontinuing antipsychotic polypharmacy, adequate trials of evidence-based treatments such as clozapine and long-acting injectable antipsychotics should be undertaken in inadequately responsive schizophrenia patients before moving to antipsychotic polypharmacy.
authors.affiliation: Florida Mental Health Institute, University of South Florida, 13301 Bruce B. Downs Blvd, Tampa, FL, USA. Electronic address: rconstantine@usf.edu.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Constantine
authors.affiliation: Florida Mental Health Institute, University of South Florida, 13301 Bruce B. Downs Blvd, Tampa, FL, USA.
authors.forename: Ross
authors.initials: R
authors.lastname: Andel
authors.affiliation: Florida Mental Health Institute, University of South Florida, 13301 Bruce B. Downs Blvd, Tampa, FL, USA.
authors.forename: Marie
authors.initials: M
authors.lastname: McPherson
authors.affiliation: Department of Psychiatry, University of Florida College of Medicine, Gainesville, FL, USA.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Tandon
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D019338:Polypharmacy; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000188:drug therapy*; D018570:Risk Assessment; D012559:Schizophrenia / Q000188:drug therapy*; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents
keywords: Antipsychotic; Clinical trial; Monotherapy; Polypharmacy; Randomized; Schizophrenia; Switch; Treatment