title: Clozapine Use in First-Episode Psychosis: The Singapore Early Psychosis Intervention Programme (EPIP) Perspective.
abstract: OBJECTIVE
  Early symptomatic response is pertinent in improving outcomes in first-episode psychosis. One of the ways in which this may be achieved is by reducing inappropriate delays in clozapine initiation. This study aimed to examine clozapine prescribing practices among clinicians by establishing the prevalence of clozapine use, identifying baseline clinical and demographic factors that were associated with clozapine use, examining outcomes in clozapine users versus nonusers, and identifying inappropriate antipsychotic prescription patterns prior to clozapine initiation.
  
  
  METHODS
  A retrospective study including all consecutive patients who had presented to the Singapore Early Psychosis Intervention Programme (EPIP) from April 2001 to June 2012 was conducted. Clinical and demographic data were extracted from the EPIP database. Incident cases of clozapine users were identified, and additional treatment histories were obtained from medical records. In addition to descriptive statistics, multivariate analysis was performed to identify factors associated with clozapine initiation.
  
  
  RESULTS
  Data from 1,603 patients were available for baseline analyses. Of these, 69 patients (4.3%) had been prescribed clozapine. Having a younger age at onset, lack of employment, a lower Global Assessment of Functioning disability score, and a higher Positive and Negative Syndrome Scale total score at baseline were factors associated with clozapine use. After adjustment was made for confounders, clozapine users were found to have attained similar rates of remission and recovery as patients who did not use clozapine. Clozapine initiation was delayed by a mean of 19.3 weeks (SD = 27.1; range, 0-117). Prior to commencing clozapine, 29.4% of patients had received antipsychotic treatments above maximum limits, whereas 75% of patients were prescribed ≥ 3 different antipsychotics (median = 3; range, 2-7).
  
  
  CONCLUSIONS
  This study has confirmed that the prescribing of clozapine is low, delayed, and preceded by dosing of antipsychotic drugs above maximum limits. Identification of the factors found to be associated with clozapine use may encourage clinicians to consider clozapine sooner in relevant patients in hopes of achieving early symptomatic response.
authors.affiliation: Department of Early Psychosis Intervention, Institute of Mental Health, 10 Buangkok View Singapore 539747, Singapore. charmaine_yz_tang@imh.com.sg.|Department of Early Psychosis Intervention, Institute of Mental Health, Singapore.
authors.forename: Charmaine
authors.initials: C
authors.lastname: Tang
authors.affiliation: Research Division, Institute of Mental Health, Singapore.
authors.forename: Mythily
authors.initials: M
authors.lastname: Subramaniam
authors.affiliation: Pharmacy Department, Institute of Mental Health, Singapore.
authors.forename: Boon Tat
authors.initials: BT
authors.lastname: Ng
authors.affiliation: Research Division, Institute of Mental Health, Singapore.
authors.forename: Edimansyah
authors.initials: E
authors.lastname: Abdin
authors.affiliation: Department of Early Psychosis Intervention, Institute of Mental Health, Singapore.
authors.forename: Lye Yin
authors.initials: LY
authors.lastname: Poon
authors.affiliation: Department of Early Psychosis Intervention, Institute of Mental Health, Singapore.
authors.forename: Swapna K
authors.initials: SK
authors.lastname: Verma
mesh_terms: D000293:Adolescent; D000328:Adult; D003024:Clozapine / Q000627:therapeutic use*; D061345:Early Medical Intervention; D005260:Female; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D012189:Retrospective Studies; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy*; D012565:Schizophrenic Psychology; D012846:Singapore; D055815:Young Adult
chemical_list: D003024:Clozapine