title: Chlorpromazine for schizophrenia: a Cochrane systematic review of 50 years of randomised controlled trials.
abstract: BACKGROUND
  Chlorpromazine (CPZ) remains one of the most common drugs used for people with schizophrenia worldwide, and a benchmark against which other treatments can be evaluated. Quantitative reviews are rare; this one evaluates the effects of chlorpromazine in the treatment of schizophrenia in comparison with placebo.
  
  
  METHODS
  We sought all relevant randomised controlled trials (RCT) comparing chlorpromazine to placebo by electronic and reference searching, and by contacting trial authors and the pharmaceutical industry. Data were extracted from selected trials and, where possible, synthesised and random effects relative risk (RR), the number needed to treat (NNT) and their 95% confidence intervals (CI) calculated.
  
  
  RESULTS
  Fifty RCTs from 1955-2000 were included with 5276 people randomised to CPZ or placebo. They constitute 2008 person-years spent in trials. Meta-analysis of these trials showed that chlorpromazine promotes a global improvement (n = 1121, 13 RCTs, RR 0.76 CI 0.7 to 0.9, NNT 7 CI 5 to 10), although a considerable placebo response is also seen. People allocated to chlorpromazine tended not to leave trials early in both the short (n = 945, 16 RCTs, RR 0.74 CI 0.5 to 1.1) and medium term (n = 1861, 25 RCTs, RR 0.79 CI 0.6 to 1.1). There were, however, many adverse effects. Chlorpromazine is sedating (n = 1242, 18 RCTs, RR 2.3 CI 1.7 to 3.1, NNH 6 CI 5 to 8), increases a person's chances of experiencing acute movement disorders, Parkinsonism and causes low blood pressure with dizziness and dry mouth.
  
  
  CONCLUSIONS
  It is understandable why the World Health Organization (WHO) have endorsed and included chlorpromazine in their list of essential drugs for use in schizophrenia. Low- and middle-income countries may have more complete evidence upon which to base their practice compared with richer nations using recent innovations.
authors.affiliation: Cochrane Schizophrenia Group, Academic Department of Psychiatry and Behavioural Sciences, University of Leeds, Leeds, LS2 9LT, UK. ceadams@cochrane-sz.org
authors.forename: Clive Elliott
authors.initials: CE
authors.lastname: Adams
authors.forename: John
authors.initials: J
authors.lastname: Rathbone
authors.forename: Ben
authors.initials: B
authors.lastname: Thornley
authors.forename: Mike
authors.initials: M
authors.lastname: Clarke
authors.forename: Jo
authors.initials: J
authors.lastname: Borrill
authors.forename: Kristian
authors.initials: K
authors.lastname: Wahlbeck
authors.forename: A George
authors.initials: AG
authors.lastname: Awad
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D002746:Chlorpromazine / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010919:Placebos; D016032:Randomized Controlled Trials as Topic; D012559:Schizophrenia / Q000188:drug therapy*; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents; D010919:Placebos; D002746:Chlorpromazine